PRECEDENTIAL


     UNITED STATES COURT OF APPEALS
          FOR THE THIRD CIRCUIT
               _____________

                  No. 12-2548
                 _____________

         UNITED STATES OF AMERICA,
                          Appellant

                       v.

HARRY KATZIN; MICHAEL KATZIN; MARK LOUIS
               KATZIN, SR.

                ______________

                APPEAL FROM THE
      UNITED STATES DISTRICT COURT
FOR THE EASTERN DISTRICT OF PENNSYLVANIA
       (D.C. Crim. Action No. 5:11-cr-00226)
     District Judge: Honorable Gene E.K. Pratter
                   ______________

              Argued March 19, 2013
                 ______________

   Before: SMITH, GREENAWAY, JR., and VAN
           ANTWERPEN, Circuit Judges.




                       1
             (Opinion Filed: October 22, 2013)
                     ______________

Robert A. Zauzmer, Esq. [ARGUED]
Emily McKillip, Esq.
Zane D. Memeger, Esq.
Thomas M. Zaleski, Esq.
Office of United States Attorney
615 Chestnut Street Suite 1250
Philadelphia, PA 19106
       Counsel for Appellant The United States of America


Thomas A. Dreyer, Esq. [ARGUED]
6 Dickinson Drive, Building 100
Chadds Ford, PA 19317-0000
      Counsel for Appellee Harry Katzin

William A. DeStefano, Esq.
Stevens & Lee
1818 Market Street, 29th Floor
Philadelphia, PA 19103-0000
      Counsel for Appellee Michael Katzin

Rocco C. Cipparone, Jr., Esq. [ARGUED]
205 Black Horse Pike
Haddon Heights, NJ 08035-0000
      Counsel for Appellee Mark Louis Katzin, Sr.

Benjamin E. Wizner, Esq.
American Civil Liberties Union
National Security Project
125 Broad Street, 18th Floor




                             2
New York, NY 10004

Catherine N. Crump, Esq. [ARGUED]
Nathan Wessler, Esq.
American Civil Liberties Union
125 Broad Street, 17th Floor
New York, NY 10004
       Counsel for Amicus Appellees the American Civil
Liberties Union Foundation

Witold J. Walczak, Esq.
Sara J. Rose, Esq.
American Civil Liberties Union
313 Atwood Street
Pittsburgh, PA 15213-0000

Catherine N. Crump, Esq. [ARGUED]
American Civil Liberties Union
125 Broad Street, 17th Floor
New York, NY 10004
      Counsel for Amicus Appellees the American Civil
      Liberties Union Foundation of Pennsylvania


Catherine N. Crump, Esq. [ARGUED]
American Civil Liberties Union
125 Broad Street, 17th Floor
New York, NY 10004

Hanni M. Fakhoury, Esq.
Marcia Hoffman, Esq.
Electronic Frontier Foundation
815 Eddy Street




                             3
San Francisco, CA 94109
      Counsel for Amicus Appellees the Electronic Frontier
Foundation

Peter Goldberger, Esq.
50 Rittenhouse Place
Ardmore, PA 19003

Catherine N. Crump, Esq. [ARGUED]
American Civil Liberties Union
125 Broad Street, 17th Floor
New York, NY 10004
      Counsel for Amicus Appellee the National Association
      of Criminal Defense Lawyers
                      ______________

                         OPINION
                      ______________

GREENAWAY, JR., Circuit Judge.

        This appeal stems from the Government‟s warrantless
installation of a Global Positioning System device (a “GPS
device” or “GPS tracker”) to track the movements of
Appellee Harry Katzin‟s van. Harry Katzin, along with his
brothers Mark and Michael (collectively, “Appellees”),
claims that attaching the GPS device without a warrant
violated the Fourth Amendment.           The United States
Government (“Appellant” or “Government”) argues that: (a) a
warrant is not required to install a GPS device; (b) even if a
warrant were required, the police were acting in good faith;
and (c) in any case, Mark and Michael lack standing to




                              4
contest admissibility of evidence recovered from Harry
Katzin‟s van.

       The instant case therefore calls upon us to decide two
novel issues of Fourth Amendment law: First, we are asked
to decide whether the police are required to obtain a warrant
prior to attaching a GPS device to an individual‟s vehicle for
purposes of monitoring the vehicle‟s movements (conduct a
“GPS search”). If so, we are then asked to consider whether
the unconstitutionality of a warrantless GPS search may be
excused for purposes of the exclusionary rule, where the
police acted before the Supreme Court of the United States
proclaimed that attaching a GPS device to a vehicle
constituted a “search” under the Fourth Amendment. For the
reasons discussed below, we hold that the police must obtain
a warrant prior to a GPS search and that the conduct in this
case cannot be excused on the basis of good faith.
Furthermore, we hold that all three brothers had standing to
suppress the evidence recovered from Harry Katzin‟s van.
We therefore will affirm the District Court‟s decision to
suppress all fruits of the unconstitutional GPS search.

I.   FACTS AND PROCEDURAL HISTORY

       Given that the issues in this matter touch upon several
forms of electronic tracking devices, we feel it necessary —
in service of our forthcoming analysis — to embark on a brief
discussion of the relevant technology before delving into the
specific circumstances surrounding Appellees.




                              5
A.   Tracking Technology

       This case concerns a “slap-on” GPS tracker, so called
because it magnetically attaches to the exterior of a target
vehicle, is battery operated, and thereby requires no electronic
connection to the automobile. The tracker uses the Global
Positioning System — a network of satellites originally
developed by the military — to determine its own location
with a high degree of specificity and then sends this data to a
central server. This check-and-report process repeats every
few minutes (depending on the tracker), thereby generating a
highly accurate record of the tracker‟s whereabouts
throughout its period of operation. The great benefit of such
a system — apart from its accuracy — is that anyone with
access to the central server can analyze or monitor the
location data remotely. These aspects make GPS trackers
particularly appealing in law enforcement contexts, where the
police can attach a tracker to some vehicle or other asset and
then remotely monitor its location and movement.

       GPS technology must be distinguished from the more
primitive tracking devices of yesteryear such as “beepers.”
Beepers are nothing more than “radio transmitter[s], usually
battery operated, which emit[] periodic signals that can be
picked up by a radio receiver.” United States v. Knotts, 

, 277 (1983). In contrast to GPS trackers, beepers do
not independently ascertain their location — they only
broadcast a signal that the police can then follow via a
corresponding receiver. Moreover, beeper signals are range-
limited: if the police move far enough away from the beeper,
they will be unable to receive the signal that the unit
broadcasts. At bottom, then, beepers are mere aids for police
officers already performing surveillance of a target vehicle.
Unlike GPS trackers, beepers require that the police expend




                               6
resources — time and manpower — to physically follow a
target vehicle.

B.   The Brothers Katzin

       A spectre was haunting Delaware, Maryland, and New
Jersey in 2009 and 2010 — the three states had been hit by a
wave of pharmacy burglaries, many of which affected Rite
Aid pharmacies. The method used in the various crimes was
largely consistent: in many cases, the alarm systems for the
pharmacies would be disabled by cutting the external phone
lines. The local police approached the FBI for help
(collectively, “the police”) and the hunt was on.

        By mid-May 2010, a suspect emerged: a local
electrician named Harry Katzin. Not only had he recently
been caught burglarizing a Rite Aid pharmacy, but he and his
brothers — Mark and Michael — had criminal histories that
included arrests for burglary and theft. Over the course of the
following months, the joint state and federal investigation
began receiving reports of seeing Harry Katzin around Rite
Aid pharmacies throughout the three states. For example, in
late October 2010, local police in Pennsylvania encountered
Harry Katzin crouching beside some bushes outside of a Rite
Aid after responding to reports of suspicious activity. The
police did not arrest him, but discovered the next day that the
phone lines to the pharmacy had been cut. The next month,
Harry Katzin, along with one of his brothers and one other
individual, was approached by the police as he sat outside of
a different Rite Aid in his Dodge Caravan. After Harry
Katzin consented to a search, the police discovered electrical
tools, gloves, and ski masks. Harry Katzin explained that
these were tools of the electrician‟s trade and the police
allowed the men to leave. The telephone lines to this Rite




                              7
Aid had also been cut. Soon thereafter, the police obtained
footage of another recently burglarized Rite Aid showing that
a vehicle similar to Harry Katzin‟s van had been parked
outside for a long period of time. As the pieces began falling
into place, the police proceeded with their next step:
electronic tracking. The police knew that Harry Katzin
regularly parked his van on a particular street in Philadelphia.
Thus, in the early hours of a mid-December morning, after
consulting with the United States Attorney‟s office, but
without obtaining a warrant, the FBI affixed a “slap-on” GPS
tracker to the exterior of Harry Katzin‟s van.

       While the police do not appear to have set a time limit
for using the GPS tracker, the device yielded the results they
were after within several days. According to the tracker,
Harry Katzin‟s van had left Philadelphia on the evening of
December 15, 2010, and had traveled to the immediate
vicinity of a Rite Aid in a neighboring town. Through use of
the device, the police could see that the van had been driven
around the town for several minutes before parking at a
specific location for over two hours. That‟s when the FBI
began to tighten the net. They alerted local police as to Harry
Katzin‟s whereabouts, but cautioned them not to approach too
closely for fear of tipping off either Harry Katzin or any
individual he may have been traveling with. When the FBI
noticed that the van was once again on the move, the call
came in: the van was to be taken.

       While state troopers stopped Harry Katzin‟s van on a
Pennsylvania highway, a squad of local police officers
investigated the Rite Aid closest to where Harry Katzin‟s van
had been parked; they found that it had been burglarized and
relayed this information to the troopers. Inside the van,
troopers found Harry at the wheel, with Mark and Michael as




                               8
passengers. From outside of the van, the troopers could see
merchandise and equipment from the burglarized Rite Aid,
including pill bottles and Rite Aid storage bins. The police
impounded the van and arrested the Katzin brothers.

        All three brothers moved to suppress the evidence
discovered in the van. The Government opposed the motions,
arguing: (a) that a warrant was not required for use of the
GPS device; (b) that the police had acted in good faith when
installing the GPS device; and (c) that Mark and Michael
lacked standing to challenge the GPS search and therefore
could not move to suppress any of the evidence. The District
Court held in favor of the brothers and suppressed all of the
evidence found in the van. United States v. Katzin, No. 11-
226, 

, *11 (E.D. Pa. May 9, 2012). This
appeal followed.

II.   JURISDICTION AND STANDARD OF REVIEW

       The District Court had jurisdiction to hear this case
pursuant to 18 U.S.C. § 3231; our jurisdiction stems from 18
U.S.C. § 3731. In reviewing a district court‟s ruling on a
motion to suppress, “we review [the] court‟s factual findings
for clear error, and we exercise de novo review over its
application of the law to those factual findings.” United
States v. Pavulak, 

, 660 (3d Cir. 2012) (citing
United States v. Coles, 

, 365 (3d Cir. 2006)).

III. GPS SEARCHES              AND     THE      WARRANT
REQUIREMENT

      The Fourth Amendment mandates that




                             9
      [t]he right of the people to be secure in their
      persons, houses, papers, and effects against
      unreasonable searches and seizures, shall not be
      violated, and no Warrant shall issue, but upon
      probable cause, supported by Oath or
      affirmation, and particularly describing the
      place to be searched, and the persons or things
      to be seized.

U.S. Const. amend. IV. Prior to 1967, the Supreme Court of
the United States interpreted this language generally to mean
that the Fourth Amendment prevented the police from
physically intruding upon an individual‟s private property for
purposes of conducting a search (the physical intrusion
theory). See United States v. Jones, 

, 949-50
(2012); see also, e.g., Olmstead v. United States, 

 (1928) (upholding the warrantless wiretapping of a
target‟s telephone lines primarily because “[t]here was no
entry of the houses or offices of the defendants”), overruled
in part by Katz v. United States, 

 (1967).1 A

1
  We note that, at times, the Supreme Court has referred to
this theory in the language of “trespass” rather than physical
intrusion. Compare Jones, 132 S. Ct. at 949-50, with Florida
v. Jardines, 

, 1414 (2013). As the law
currently stands, we think the latter term — “physical
intrusion” — is the more appropriate. See Jardines, 133 S.
Ct. at 1420-21 (Alito, J., dissenting) (criticizing the Supreme
Court‟s most recent application of the physical intrusion
theory and noting that “trespass law provides no support for
the Court‟s holding today”); Silverman v. United States, 

, 511 (1961) (“[W]e need not pause to consider
whether or not there was a technical trespass under the local




                              10
change came in 1967 with the decision in Katz v. United
States, which involved the warrantless wiretapping of a public
phone booth. 

. In Katz, the Court announced
that the Fourth Amendment “protects people, not places,” id.
at 351, a principle that eventually became embodied in what
Justice Harlan termed an individual‟s “reasonable expectation
of privacy” (the privacy theory), id. at 360-61 (Harlan, J.,
concurring). In subsequent years, the privacy theory became
the driving force behind Fourth Amendment jurisprudence,
while the physical intrusion theory lay dormant. See, e.g.,
United States v. Santillo, 

, 632 (3d Cir. 1975)
(noting that “the trespassory concepts [in early Fourth
Amendment jurisprudence] . . . have since been discredited”
(footnotes omitted) (citing Katz, 389 U.S. at 352-53)).

A.   Beepers, GPS Devices, and the Fourth Amendment

       It was in this context that courts began grappling with
the constitutionality of using tracking devices. For purposes
of our discussion, we begin with the Fifth Circuit‟s 1981
decision in United States v. Michael, 

 (5th Cir.
1981) (en banc), which considered the warrantless use of a
beeper for surveillance of a suspected drug manufacturer. In
Michael, the court assumed that installation of the beeper on
the exterior of a van constituted a search before holding that
the DEA agents‟ conduct was constitutional since they acted
based on reasonable suspicion. Id. at 256-59 (holding that
defendant had “reduced” privacy expectations in the

property law relating to party walls. Inherent Fourth
Amendment rights are not inevitably measurable in terms of
ancient niceties of tort or real property law.” (footnote
omitted)).




                             11
movement of his automobile and that the use of a beeper was
minimally intrusive). A pair of dissenting opinions argued
that, among other things, the DEA agents were required to
obtain a warrant because they physically intruded upon the
defendant‟s property (i.e., his car). See, e.g., id. at 260-70
(Tate, J., dissenting).

       Two years later, the Supreme Court took up the beeper
issue, ultimately holding that concealing a beeper inside of a
container that was then loaded onto a target‟s vehicle did not
constitute a search, where the beeper‟s placement was
accomplished with the container owner‟s consent. United
States v. Knotts, 

, 279-80, 285 (1983). In so
doing, the Supreme Court explained that “[a] person traveling
in an automobile on public thoroughfares has no reasonable
expectation of privacy in his movements from one place to
another.” Id. at 281. Nonetheless, the Court‟s ruling was not
unequivocal, with the Majority cautioning that twenty-four
hour, “dragnet type law enforcement practices” could
implicate “different constitutional principles.” Id. at 283-84.

       The Supreme Court returned to beepers the following
year when it decided United States v. Karo, 

(1984), which centered on the DEA‟s use of a beeper to
collect information regarding the whereabouts of objects
inside a private residence. In Karo, the DEA had once again
secreted a beeper inside of a container — also with the
container owner‟s consent — and ensured that the container
would be loaded into the target‟s vehicle. Id. at 708-09. The
agents then used the beeper to track the vehicle to various
locations and determined that the beeper-concealing container
had been brought inside several residences (something that
they could not verify with visual surveillance). Id. at 709-10.
In holding that use of the beeper was unconstitutional under




                              12
those circumstances, the Court explained that, unlike in
Knotts — where information was “voluntarily conveyed to
anyone who wanted to look” — the information obtained by
monitoring the beeper while inside a private residence gave
the DEA information “that could not have been visually
verified.” Id. at 715 (internal quotation marks omitted). In a
partial dissent, Justice Stevens (joined by Justices Brennan
and Marshall) argued that placing the beeper inside a
container, which was then loaded into the target‟s vehicle,
implicated both a “seizure and a search within the meaning of
the Fourth Amendment.” Id. at 728 (Stevens, J., dissenting in
part).

        After the beeper-centered decisions in Michael, Knotts,
and Karo, technological advances heralded the advent of a
new electronic surveillance device: the GPS tracker. One of
the first decisions to address the constitutionality of this new
technology was United States v. McIver, 

 (9th
Cir. 1999). In McIver, the Ninth Circuit rejected defendant‟s
argument that installing a GPS device (along with a beeper)
on the “undercarriage of [the defendant‟s automobile]”
constituted a “seizure of the vehicle.” Id. at 1127 (“McIver
did not present any evidence that the placement of the
magnetized tracking devices deprived him of dominion and
control of his [vehicle], nor did he demonstrate that the
presence of these objects caused any damage to the electronic
components of the vehicle.”). The court also concluded that,
because McIver could demonstrate no reasonable expectation
of privacy in the exposed undercarriage of his car, the use of
the electronic devices did not constitute a search under the
Fourth Amendment. Id. at 1126-27.

      The Seventh Circuit followed suit in 2007, with Judge
Posner explaining that attaching a GPS device to a target




                              13
vehicle did not constitute a search because such a device
merely substitutes for “following a car on a public street,” an
activity that “is unequivocally not a search within the
meaning of the [Fourth Amendment].” United States v.
Garcia, 

, 997 (7th Cir. 2007). However,
echoing the Supreme Court‟s concerns in Knotts, the Seventh
Circuit warned that it might need to reevaluate its conclusion
if faced with a case concerning use of GPS technology for
mass surveillance. Id. at 998.

       Three years later, the Ninth Circuit returned to the
topic of GPS tracking, reaffirming its conclusion that
attaching a GPS tracker to the undercarriage of a vehicle did
not constitute a search. United States v. Pineda-Moreno, 

, 1214-15 (9th Cir. 2010). The appellant filed a
petition for rehearing en banc, and though the Ninth Circuit
denied the petition, Chief Judge Kozinski issued a fiery
dissent from the denial, accusing the Pineda-Moreno majority
of being “inclined to refuse nothing” to the needs of law
enforcement. United States v. Pineda-Moreno, 

, 1121 (9th Cir. 2010) (Kozinski, C.J., dissenting). In his
dissent, the Chief Judge noted that GPS devices “have little in
common with the primitive devices in Knotts,” in part
because, unlike GPS devices, beepers “still require[] at least
one officer — and usually many more — to follow the
suspect.” Id. at 1124. Thus, the dissent noted, while “[y]ou
can preserve your anonymity from prying eyes, even in
public, by traveling at night, through heavy traffic, in crowds,
by using a circuitous route, disguising your appearance,
passing in and out of buildings and being careful not to be
followed,” there is “no hiding from the all-seeing network of
GPS satellites that hover overhead, which never sleep, never
blink, and never lose attention.” Id. at 1126.




                              14
       That same year, the Eighth Circuit became the third of
our sister courts to say that attaching a GPS device to a target
car was not a constitutional violation. United States v.
Marquez, 

, 609-10 (8th Cir. 2010). While the
Marquez court based its ruling on standing grounds, it still
announced — albeit in dicta — that “[w]hen electronic
monitoring does not invade upon a legitimate expectation of
privacy, no search has occurred.” Id. at 609 (“A person
traveling via automobile on public streets has no reasonable
expectation of privacy in his movements from one locale to
another.” (citing Knotts, 460 U.S. at 281)).

       Later that year, the D.C. Circuit split from our sisters,
holding that attaching a GPS device to a defendant‟s vehicle
constituted a search under the Fourth Amendment that
required the police to obtain a warrant. United States v.
Maynard, 

 (D.C. Cir. 2010). In so doing, the
court rejected the Knotts-based argument that a driver‟s
movements are exposed to the public and therefore do not
constitute information shielded by the Fourth Amendment.
Id. at 560 (“[W]e hold the whole of a person‟s movements
over the course of a month is not actually exposed to the
public because the likelihood a stranger would observe all
those movements is not just remote, it is essentially nil.”). At
the same time, the court in Maynard rejected the applicability
of the automobile exception to the warrant requirement,
holding that while the exception “permits the police to search
a car without a warrant if they have reason to believe it
contains contraband[, it] . . . does not authorize them to install
a tracking device on a car without the approval of a neutral
magistrate.” Id. at 567. A year later, the Supreme Court
granted certiorari, changing the name to United States v.
Jones. 

 (2011).




                               15
       In reviewing the Maynard decision (now called Jones),
the Supreme Court held that magnetically attaching a GPS
device to a suspect‟s automobile constituted a search for
purposes of the Fourth Amendment. Jones, 132 S. Ct. at 949.
Rather than focusing on whether the owner of the vehicle had
a reasonable expectation of privacy while driving the car over
public streets, the Court (with Justice Scalia writing for the
majority) concluded that attaching a GPS device to a target
car constituted a physical intrusion upon the vehicle owner‟s
private property. Id. (“The Government physically occupied
private property for the purpose of obtaining information.
We have no doubt that such a physical intrusion would have
been considered a „search‟ within the meaning of the Fourth
Amendment when it was adopted.”).

       Justice Alito concurred in the judgment, but did not
join the majority‟s opinion. Id. at 957 (Alito, J., concurring).
In his opinion — joined by Justices Ginsburg, Breyer, and
Kagan — the appropriate Fourth Amendment analysis was
the “reasonable expectation of privacy” inquiry under Katz.
The outcome would be no different if the Court had applied
Katz, the concurrence argued, because “society‟s expectation
has been that law enforcement agents and others would not —
and indeed, in the main, simply could not — secretly monitor
and catalogue every single movement of an individual‟s car
for a very long period” of time. Id. at 964.

       Justice Sotomayor, who joined the majority, also filed
a concurrence. Id. at 954 (Sotomayor, J., concurring). And
while she agreed with portions of Justice Alito‟s reasoning,
she nonetheless rebuked the concurring Justices for
potentially countermanding an “irreducible constitutional
minimum:       When the Government physically invades
personal property to gather information, a search occurs.” Id.




                              16
at 955. Moreover, Justice Sotomayor argued that GPS
devices present law-enforcement agencies with a low-cost,
low-resource method of tracking citizens. As such, even
short-term surveillance constituted an impermissible search
under the Fourth Amendment. Id. at 955-57 (calling, also, for
potentially reassessing the privacy interests individuals enjoy
in information disclosed to third parties so as to account for
the new realities of the digital age).

        Among the issues that Jones left open, however, was
whether warrantless use of GPS devices would be
“reasonable — and thus lawful — under the Fourth
Amendment [where] officers ha[ve] reasonable suspicion, and
indeed probable cause” to execute such searches. Id. at 954
(citation and internal quotation marks omitted). The instant
case squarely presents this very issue for our consideration.2
2
  At the time of this writing, we are not aware of — nor has
either party brought to our attention — any decision by one of
our sister circuits that directly and definitively resolves the
matter. As our brethren in the First Circuit noted earlier this
year:

Few courts (and no circuits that we know of) have grappled
with the warrant question so far, largely because the searches
at issue in recent cases occurred pre-Jones, allowing the
government to argue, and a number of courts to find, that the
good-faith exception [to the exclusionary rule] would apply
even if the searches were unconstitutional.

United States v. Sparks, 

, 62 (1st Cir. 2013). As
we explain at greater length below, we do not believe that the
good-faith exception applies in this case and consequently
take on the warrant issue.




                              17
We therefore turn now to a consideration of the Fourth
Amendment‟s warrant requirement and the various — albeit
circumscribed — exceptions thereto.

B.   The Warrant Requirement and Its Exceptions

        The Fourth Amendment does not protect individuals
from all searches, just unreasonable ones. Indeed, as the
Supreme Court has noted: “[T]he ultimate measure of the
constitutionality    of    a    governmental     search     is
„reasonableness.‟” Vernonia Sch. Dist. 47J v. Acton, 

, 652 (1995). “[W]hether a particular search meets
the reasonableness standard is judged by balancing its
intrusion on the individual‟s Fourth Amendment interests
against its promotion of legitimate governmental interests.”
Id. at 652-53 (internal quotation marks omitted). Under this
“general . . . approach,” courts look to the “totality of the
circumstances” in performing this balancing test. United
States v. Knights, 

, 118 (2001) (internal
quotation marks omitted).

       More often than not, courts “strike this balance in
favor of the procedures described by the Warrant Clause of
the Fourth Amendment.” Skinner v. Ry. Labor Execs.’ Ass’n,

, 619 (1989). Thus, “[i]t remains a cardinal
principle that searches conducted outside the judicial process,
without prior approval by judge or magistrate, are per se
unreasonable under the Fourth Amendment — subject only to
a few specifically established and well-delineated
exceptions.” United States v. Harrison, 

, 306
(3d Cir. 2012) (internal quotation marks omitted). This
protection applies to both “„houses‟ and „effects,‟” barring the
presence of some “„exceptional circumstances‟” that would
permit an exception. See United States v. Jeffers, 

48, 51 (1951) (quoting Johnson v. United States, 

,
14 (1948)).

        We therefore begin with the following observation:
under the physical intrusion theory of the Fourth Amendment,
the police actions in this case — i.e., physical entry upon and
occupation of an individual‟s house or effects for purposes of
ongoing GPS tracking — are highly disconcerting. In
Silverman v. United States, 

 (1961), the police,
acting without a warrant, had surreptitiously driven a “spike
mic” (a long spike capable of picking up sound) through the
wall of a neighboring house and into the heating duct of the
defendant‟s home. Id. at 506-07. The Court proclaimed this
to be “beyond the pale of even those decisions in which a
closely divided Court has held that eavesdropping
accomplished by other than electronic means did not amount
to an invasion of Fourth Amendment rights.” Id. at 509-10;
id. at 511-12 (“This Court has never held that a federal officer
may without warrant and without consent physically entrench
into a man‟s office or home, there secretly observe or listen,
and relate at the man‟s subsequent criminal trial what was
seen or heard.” (emphasis added)). While the Fourth
Amendment recognizes a difference between the invasion of
a “store, dwelling house, or other structure . . . of which a . . .
warrant readily may be obtained and a search of a ship, motor
boat, wagon, or automobile . . . where it is not practicable to
secure a warrant,” that difference, on its own, still mandates
that a warrantless search of a car be based on probable cause
— and, even then, only in a highly circumscribed universe of
cases. Carroll v. United States, 

, 153 (1925).3

3
 We address the “automobile exception,” first recognized in
Carroll, in greater detail below.




                                19
        We thus have no hesitation in holding that the police
must obtain a warrant prior to attaching a GPS device on a
vehicle, thereby undertaking a search that the Supreme Court
has compared to “a constable‟s concealing himself in the
target‟s coach in order to track its movements.” Jones, 132 S.
Ct. at 950 n.3. In the following section, therefore, we analyze
whether any additional considerations weigh in favor of
finding warrantless GPS searches to be reasonable.

1. Valid, Warrantless Searches Based on Less than
Probable Cause

        The Government first argues that the warrantless use
of a GPS device in this case constitutes a reasonable search
because the police action was based on reasonable suspicion.4
In service of this argument, the Government posits that
“[s]ince Terry v. Ohio, 

 (1968), the Court has
identified various law enforcement actions that qualify as
Fourth Amendment searches or seizures, but that may
nevertheless be conducted without a warrant or probable
cause.” (Appellant Br. at 23.) This is true. The Government
cites to three general categories of cases that permit
warrantless searches based on less than probable cause:
“special needs” cases, decisions addressing circumstances in
which individuals have lessened privacy interests, and the
progeny of Terry v. Ohio. We consider each category in turn
and find that none apply to the instant matter.




4
 We assume, without deciding, that the police had reasonable
suspicion for purposes of our analysis.




                              20
a.   The “Special Needs” Cases

       As the Supreme Court has explained: “We have
recognized exceptions to th[e Warrant Clause] when special
needs, beyond the normal need for law enforcement, make the
warrant and probable-cause requirement impracticable.”
Skinner, 489 U.S. at 619-20 (internal quotation marks
omitted) (collecting cases). Thus, so long as the “primary
purpose” is not to “uncover evidence of ordinary criminal
wrongdoing,” City of Indianapolis v. Edmond, 

,
42 (2000), courts should “balance the governmental and
privacy interests to assess the practicality of the warrant and
probable-cause requirements in the particular context,”
Skinner, 489 U.S. at 619. See also United States v. Ward, 

, 342 (3d Cir. 1997). Such “special needs” cases,
many of which permit searches without any particularized
suspicion, constitute a “closely guarded category” of Fourth
Amendment jurisprudence. Ferguson v. City of Charleston,

, 77 (2001) (internal quotation marks omitted).

        In the instant case, the reasoning behind the “special
needs” doctrine is inapposite. The Government cannot
articulate a particularized interest, other than a generalized
interest in law enforcement.         Indeed, the Government
contends that if officers are required to obtain a warrant and
have probable cause prior to executing a GPS search,
“officers could not use GPS devices to gather information to
establish probable cause, which is often the most productive
use of such devices.” (Appellant Br. at 27 (emphasis added).)
This statement — which wags the dog rather vigorously —
runs headlong into Ferguson‟s admonition that, to qualify for
a “special needs” exception, the primary purpose of a search
cannot be to “generate evidence for law enforcement
purposes.” 532 U.S. at 83 (emphasis omitted); Edmond, 531




                              21
U.S. at 48 (finding that a search did not qualify under the
“special needs” doctrine where the “primary purpose of the
[search] is ultimately indistinguishable from the general
interest in crime control”).5

b.   Cases of Diminished Privacy Expectations

       Still, the “special needs” cases are not the only
decisions to permit warrantless searches based on less than
probable cause. The Government also cites a number of cases
that address situations where the targets of a search enjoyed a
lower expectation of privacy.6 See, e.g., United States v.

5
  The Government contends that requiring a warrant prior to
GPS searches would “seriously impede the government‟s
ability to investigate drug trafficking, terrorism, and other
crimes.” (Appellant Br. at 27.) We fail to see how such a
conclusory assertion suffices to except GPS searches from the
requirements of the Fourth Amendment‟s Warrant Clause.
Doubtless, we are aware of the dangers posed by terrorism
and comparably reprehensible criminal activity. However,
we would work a great disservice by permitting the word
“terrorism” (in the absence of any other information or
circumstance) to act as a skeleton key to the liberties
guaranteed under the Constitution.
6
  The seemingly paradoxical exercise of analyzing a search
based on physical intrusion under the rubric of privacy
expectations does not escape our notice. Still, as the Supreme
Court noted in Jones: “The Katz reasonable-expectation-of-
privacy test has been added to, not substituted for, the
common-law trespassory test.” Jones, 132 S. Ct. at 952.
Moreover, we note that even before Katz, the Supreme Court
was balancing the “need for effective law enforcement




                              22
Knights, 

, 121 (2001) (“When an officer has
reasonable suspicion that a probationer subject to a search
condition is engaged in criminal activity, there is enough
likelihood that criminal conduct is occurring that an intrusion
on the probationer‟s significantly diminished privacy interests
is reasonable.”). We do not think such reasoning is
applicable to this case.

       The police executed a GPS search against an
individual — Harry Katzin — who, at least when the police
attached the GPS device, enjoyed the full breadth of privacy
interests owed to him under the Constitution. That the search
was executed on a car is, likewise, unpersuasive. While the
Supreme Court has acknowledged that individuals enjoy a
lowered expectation of privacy in their cars, United States v.
Chadwick, 

, 12 (1977), abrogated by California v.
Acevedo, 

 (1991), absent circumstances that are
not present in this case, the police must still have probable
cause, Acevedo, 500 U.S. at 579-80.

c.   Terry and Its Progeny

       In no small part, the Government argues that the
warrantless use of slap-on GPS devices is permissible based
on reasonable suspicion under the principles of Terry v. Ohio,

. In Terry, the Supreme Court held that a police
officer could “stop” an individual on the street for questioning

against the right of privacy” in considering whether a
particular situation constituted an exception to the Fourth
Amendment‟s warrant requirement. Johnson, 333 U.S. at 14-
15 (considering warrantless searches based on probable
cause).




                              23
and then “frisk” him to ascertain whether the individual was
carrying weapons. Terry, 392 U.S. at 22-27. More
specifically, the Court held that a warrantless search — the
stop — was permissible when based on less than probable
cause if the “police officer observes unusual conduct which
leads him reasonably to conclude in light of his experience
that criminal activity may be afoot.” Id. at 30. As for the
search — the frisk — the Court explained that a search was
permitted when the officer reasonably believed that “the
person[] with whom he is dealing may be armed and
presently dangerous . . . and where nothing in the initial
stages of the encounter serves to dispel his reasonable fear for
his own or others‟ safety.” Id. Such a search, given that it is
performed without probable cause, “must be limited to that
which is necessary for the discovery of weapons which might
be used to harm the officer or others nearby, and may
realistically be characterized as something less than a „full‟
search.” Id. at 26. The Terry framework has since expanded
to include situations where, for example, an automobile has
been stopped. See, e.g., Michigan v. Long, 

(1983); Pennsylvania v. Mimms, 

 (1977); United
States v. Yamba, 

 (3d Cir. 2007).

        We find Terry and its progeny to be inapposite in this
situation. While the frisk in Terry involved a pat-down of an
individual, that search was limited to a specific instance in
time (and limited to ascertaining whether the individual was
armed or otherwise posed a danger to officer safety). A GPS
search, in contrast, is an ongoing, vastly broader endeavor.7

7
  The Government argues that “[a] Terry search is the
paradigmatic example of a law enforcement action, absent
„special needs‟ . . . , in which the balancing of law




                              24
Cf. Berger v. New York, 

, 59 (1967) (noting that
“eavesdropping for a two-month period is the equivalent of a
series of intrusions, searches, and seizures”). Over the course
of the GPS tracker‟s operation, the device can “generate[] a
precise, comprehensive record of a person‟s public
movements that reflects a wealth of detail about her familial,
political, professional, religious, and sexual associations.”
Jones, 132 S. Ct. at 955 (Sotomayor, J., concurring).8


enforcement interests and privacy rights yields a standard less
than probable cause.” (Appellant Br. at 33.) This is
incorrect. While the Court found that the “stop” was
permissible despite merely serving a “legitimate investigative
function,” that same rationale did not apply to the “frisk.”
Terry, 392 U.S. at 22-24. Rather, the Court explicitly noted,
in evaluating the search of an individual‟s person, that it was
“now concerned with more than the governmental interest in
investigating crime.”        Id. at 23 (emphasis added).
Specifically, the Terry court looked to the “more immediate
interest of the police officer in taking steps to assure himself
that the person with whom he is dealing is not armed with a
weapon that could unexpectedly and fatally be used against
him.” Id. The police, in attaching a GPS device to a car, are
not looking for weapons and generally are not attempting to
safeguard anyone‟s immediate safety — they are attempting
to investigate crime.
8
  The Government also seems to suggest that our evaluation
should turn on how long the GPS unit remained attached to
Harry Katzin‟s van. (Appellant Br. at 25.) It is unclear,
however, whether such a test would prove workable. It is not
apparent whether, pursuant to such a test, the government
would need to know how long a GPS search would last or




                              25
       Ultimately, we disagree with the Government‟s
arguments advocating a “reasonable suspicion” standard.
While the interests the police wished to further in this case are
certainly important, the same interests arise in every
investigation where the police have a potential suspect. We
are hard pressed to say, therefore, that the police can —
without warrant or probable cause — embark on a lengthy
program of remote electronic surveillance that requires almost
no law enforcement resources and physically intrudes upon
an ordinary citizen‟s private property. Consequently, we hold
that — absent some highly specific circumstances not present
in this case — the police cannot justify a warrantless GPS
search with reasonable suspicion alone.9


whether they could, upon reaching some threshold duration,
request a warrant from the courts for further GPS
surveillance. We need not definitively resolve this question
now, however. In this case, it was only by dint of
coincidence that the GPS surveillance lasted for a mere
handful of days.
9
  In support of its position, the Government points to the
Eighth Circuit‟s decision in Marquez and the Fifth Circuit‟s
decision in Michael. In Marquez, the court suggested that
“[w]hen electronic monitoring does not invade upon a
legitimate expectation of privacy, no search has occurred.”
605 F.3d at 610 (“[W]hen police have reasonable suspicion
that a particular vehicle is transporting drugs, a warrant is not
required when, while the vehicle is parked in a public place,
they install a non-invasive GPS tracking device on it for a
reasonable period of time.”). In Michael, the Fifth Circuit
explained that the “reduced” expectation of privacy with
respect to the movement of an automobile and the




                               26
nonintrusive nature of the procedure permitted DEA agents to
install a beeper on the defendant‟s car. 645 F.2d at 257-58
(“The actual installation of the beeper was much less intrusive
than the typical stop and frisk. Michael . . . was not detained
or questioned; he suffered no indignity; nothing from the
interior of the van was seized or searched; indeed, nothing
even from the van‟s exterior was removed.” (footnote
omitted)).

The Government‟s reliance is misplaced. Both Michael and
Marquez were decided prior to Jones, and thus did not have
the benefit of: (a) the Court‟s reliance on the pre-Katz
trespass theory of the Fourth Amendment or (b) Justice
Sotomayor‟s concurrence.       Moreover, both cases are
inapposite: In Marquez, the court found that the defendant
lacked standing to challenge the use of the GPS device and
therefore never reached the question of whether such use
constituted an unreasonable search. 605 F.3d at 609. The
Eighth Circuit‟s discussion of reasonable suspicion is
therefore dicta, coming only while the court was musing on
what would happen “[e]ven if [the defendant] had standing.”
Id. In Michael, the Fifth Circuit focused on a beeper —
which is markedly different from a GPS device — and its
decision is therefore distinguishable. 645 F.2d 256-59.
Additionally, both decisions run up against the holding in
Maynard, where the D.C. Circuit explained that warrantless
installation of a GPS device by the police was per se
unreasonable under the Fourth Amendment. 615 F.3d at 566-
67.




                              27
2. Valid, Warrantless Searches Based on Probable
Cause

       As an alternative, the Government suggests that
warrantless GPS searches can be constitutional if the police
have probable cause, pointing principally to a line of cases
addressing the “automobile exception” to the warrant
requirement.10 We do not agree.11

10
   We note that a warrantless search based on probable cause
is also reasonable in the presence of certain “exigent
circumstances” that “make the needs of law enforcement so
compelling that [a] warrantless search is objectively
reasonable under the Fourth Amendment.” Kentucky v. King,

, 1856 (2011) (internal quotation marks
omitted). Such exigent circumstances include, but are not
limited to, “hot pursuit of a suspected felon, the possibility
that evidence may be removed or destroyed, and danger to the
lives of officers or others.” United States v. Coles, 

, 366 (3d Cir. 2006) (“In these limited situations, the need
for effective law enforcement trumps the right of privacy and
the requirement of a search warrant, thereby excusing an
otherwise unconstitutional intrusion.” (footnote omitted)). In
this case, we perceive (and the Government points to) no
exigency that would have justified the police in immediately
searching Harry Katzin‟s van. We do not discount, therefore,
the possibility that under highly specific circumstances —
such as where life is on the line, say — the police can justify
undertaking a warrantless GPS search based on probable
cause.
11
  Here we also assume, without deciding, that the police had
probable cause for purposes of our analysis.




                              28
        Generally speaking, a warrantless search is not
rendered reasonable merely because probable cause existed
that would have justified the issuance of a warrant. See Vale
v. Louisiana, 

, 34 (1970); see also Johnson, 333
U.S. at 14 (“Any assumption that evidence sufficient to
support a magistrate‟s disinterested determination to issue a
search warrant will justify the officers in making a search
without a warrant would reduce the Amendment to a nullity
and leave the people‟s homes secure only in the discretion of
police officers.”).         However, under the “automobile
exception,” we permit “warrantless searches of any part of a
vehicle that may conceal evidence . . . where there is probable
cause to believe that the vehicle contains evidence of a
crime.” United States v. McGlory, 

, 343 (3d Cir.
1992) (internal quotation marks omitted); see also United
States v. Ross, 

, 825 (1982) (“If probable cause
justifies the search . . . , it justifies the search of every part of
the vehicle and its contents that may conceal the object of the
search.”); United States v. Burton, 

, 100 (3d Cir.
2002) (holding that warrantless searches of an automobile are
permitted if “probable cause exists to believe it contains
contraband” (internal quotation marks omitted)). That said,
the Supreme Court has recognized that “[t]he word
„automobile‟ is not a talisman in whose presence the Fourth
Amendment fades away and disappears.” Coolidge v. New
Hampshire, 

, 461-62 (1971) (discussing the
automobile exception in the context of exigent
circumstances).12 Indeed, the automobile exception does not

12
   The automobile exception began as part of the “exigent
circumstances” jurisprudence. Carroll, 267 U.S. at 153
(noting that the Fourth Amendment made a distinction for
searches of automobiles since “it is not practicable to secure a




                                 29
validate all warrantless automobile searches, but instead is
“unquestionably [a] specifically established and well
delineated” exception. Ross, 456 U.S. at 824 (internal
quotation marks omitted).         Thus, “„[t]he scope of a
warrantless search of an automobile . . . is defined by the
object of the search and the places in which there is probable
cause to believe that it may be found.‟” Acevedo, 500 U.S. at
579-80 (quoting United States v. Ross, 

, 824
(1982)).

       We hold that the automobile exception is inapplicable
here. The key distinction in this case is the type of search at
issue.   While the Supreme Court has stated that the
automobile exception permits a search that is “no broader and
no narrower than a magistrate could legitimately authorize by
warrant,” Ross, 456 U.S. at 825, the search is still limited to a

warrant, because the vehicle can be quickly moved out of the
locality or jurisdiction in which the warrant must be sought”).
Later cases expanded on this rationale, adding further
justification for why the police need not obtain a search
warrant for the car. Most significantly, after the Katz
decision had given precedential imprimatur to the language of
“privacy,” the Court explained in United States v. Chadwick,
that “„[o]ne has a lesser expectation of privacy in a motor
vehicle because its function is transportation and it seldom
serves as one‟s residence or as the repository of personal
effects.‟” 433 U.S. at 12 (quoting Cardwell v. Lewis, 

, 590 (1974)). Finally, the Supreme Court severed
the connection between the automobile exception and exigent
circumstances, holding that the exception “has no separate
exigency requirement” at all. Maryland v. Dyson, 

, 466 (1999).




                               30
discreet moment in time. For example, the exception permits
the police to enter upon and search a vehicle to ascertain
whether it indeed contains the evidence that they suspect is
inside. Thus, assuming — as we said we would — that the
police had probable cause to believe that Harry Katzin‟s van
contained some form of contraband, they would have been
justified in entering “any part of [the] vehicle that may
conceal evidence.” McGlory, 

 (emphasis
added). Attaching and monitoring a GPS tracker is different:
It creates a continuous police presence for the purpose of
discovering evidence that may come into existence and/or be
placed within the vehicle at some point in the future.

       It is no argument, then, to say that a GPS search
presents the type of circumstances that usually trigger the
automobile exception. It does not. While the police are still
physically intruding into a target vehicle for evidence-
gathering purposes, a GPS search extends the police intrusion
well past the time it would normally take officers to enter a
target vehicle and locate, extract, or examine the then-existing
evidence.13 For similar reasons, the case in favor of applying
the automobile exception fares no better if we look to the
13
    We recognize that the Supreme Court has sanctioned
warrantless searches under the automobile exception that, for
example, have occurred some time after the police first
impounded a vehicle. See, e.g., United States v. Johns, 

, 485-88 (1985). We think this to be of no moment
for our purposes. In cases such as Johns the search at issue
still occurs at a specific point in time and is specifically
limited in its scope to “places in which there is probable cause
to believe that [contraband] may be found.” Id. at 485-86
(internal quotation marks omitted).




                              31
“ready mobility” of the target vehicle. Burton, 288 F.3d at
100 (“[T]he „ready mobility‟ of automobiles permits their
search based only on probable cause.”); see also Maryland v.
Dyson, 

, 467 (1999) (noting that “the automobile
does not have a separate exigency requirement,” partly
because vehicles are “readily mobile”). Simply put: attaching
and monitoring a GPS tracker does not serve the purposes
animating the automobile exception. As has already been
said: the automobile exception permits the police to intrude
into a vehicle to retrieve or examine then-existing evidence.
A GPS search does not deal with existing evidence, but with
future evidence that the police suspect could come into being.
That is a worthy goal, to be sure, but it cannot absolve law
enforcement personnel of the warrant requirement. As the
Government points out, the Supreme Court‟s automobile
exception decisions are “„based on the practicalities of the
situations presented.‟” (Appellant Br. at 40 (quoting Ross,
456 U.S. at 807 n.9).) However, the Government seems to
overlook that the power to create an ongoing, near-invisible
police presence via a GPS tracker skews the “realistic
appraisal of the . . . protection that a contrary rule would
provide” from the “relatively minor” to the decidedly major.
(Id. (discussing protection for “privacy interests”).)

       Additionally, we think that the “pervasive regulation
of vehicles capable of traveling on the public roadways” is of
no moment for purposes of the instant case. California v.
Carney, 

, 392 (1985). True, such pervasive
regulation gave rise to the understanding that an individual is
“accorded less privacy in [his] automobile[].” Id. Indeed,
this principle animated the Supreme Court‟s statement that
“[e]ven in cases where an automobile was not immediately
mobile, the lesser expectation of privacy resulting from its




                              32
use as a readily mobile vehicle justified application of the
vehicular exception.” Id. at 391. Nevertheless, we still hold
that a GPS search is sufficiently different from the type of
search sanctioned by the automobile exception jurisprudence
— and that, as a consequence, even the extensive scheme of
regulation now affecting motorists does not permit the
government to dispense with asking for permission from a
neutral magistrate when seeking to physically intrude upon a
target vehicle for longer than is necessary to locate, remove,
and/or verify the presence of already-existing evidence of
criminal wrongdoing. Cf. Delaware v. Prouse, 

,
662-63 (1979) (noting, in the context of Terry stops, that
“[w]ere the individual subject to unfettered governmental
intrusion every time he entered an automobile, the security
guaranteed by the Fourth Amendment would be seriously
circumscribed”).14


14
   The Government also points to New York v. Class, 

 (1986), for the proposition that a warrantless, minimally
intrusive search of a vehicle is permitted where the police
have probable cause. (Appellant Br. at 37). In Class, the
police had stopped a car for various traffic violations. After
the driver exited the vehicle of his own accord, an officer
approached the vehicle in order to copy the VIN number on
the dashboard. Finding his view obscured, the officer reached
into the car to move some papers and, in the process,
observed the handle of a gun. Inevitable results followed.
Class, 475 U.S. at 107-09. A brief look at the underlying
reasoning of Class, however, demonstrates that it is
inapposite: the Court reasoned that the brief search served
several important government needs beyond a basic interest
in law enforcement, including “the governmental interest in




                             33
       Ultimately, in executing a GPS search, the police were
not attempting to recover or ascertain the presence of
evidence already present in Harry Katzin‟s vehicle. If they
were, the automobile exception would have sanctioned their
search in so far as it allowed them to enter Harry Katzin‟s van
and retrieve and/or verify the presence or absence of the
sought-after evidence. It would not (and, indeed, did not)
permit them to leave behind an ever-watchful electronic
sentinel in order to collect future evidence. Were we to hold
otherwise, we would unduly expand the scope of the
automobile exception well past its “specifically established
and well delineated” contours, Ross, 456 U.S. at 824,
permitting the police to intrude indefinitely upon a target
vehicle based solely on the prospect that it will, in the future,
contain some contraband or be used during the commission of
a crime.

       For these reasons we hold that the warrantless search
in this case was not justifiable based solely on reasonable
suspicion or probable cause, was thereby unreasonable, and
consequently violated the Fourth Amendment.

IV.   The Exclusionary Rule & the Good Faith Exception

      Having held that the police were required to obtain a
warrant prior to executing their GPS search of Harry Katzin‟s
van, we now consider whether the evidence uncovered as a

highway safety” and a “concern for the officers‟ safety.” Id.
at 118. Here, neither of the interests is directly served.
Accord Jones, 132 S. Ct. at 952 (holding that Class is
inapplicable to GPS searches because “attaching [a] device to
the [car]” may have resulted in a different outcome).




                               34
result of their unconstitutional actions should be suppressed.
We hold that it should.

A.   Exclusionary Rule Jurisprudence

       While the Fourth Amendment protects the “right of the
people to be secure in their persons, houses, papers, and
effects, against unreasonable searches and seizures[, it] says
nothing about suppressing evidence obtained in violation of
this command.” Davis v. United States, 

,
2426 (2011) (internal quotation marks omitted).
Nevertheless, to “compel respect for the constitutional
guaranty,” the Supreme Court created the exclusionary rule.
Elkins v. United States, 

, 217 (1960). The rule
mandates that evidence obtained in violation of the Fourth
Amendment should not be available at trial. Herring v.
United States, 

, 139 (2009). However, “that a
Fourth Amendment violation occurred . . . does not
necessarily mean that the exclusionary rule applies.” Id. at
140.

       As the Supreme Court has made plain, “exclusion has
always been our last resort, not our first impulse.” Id.
(internal quotation marks omitted). To that end, the Supreme
Court has recognized the existence of a “good faith”
exception to the exclusionary rule in cases where the police
“act[ed] with an objectively reasonable good-faith belief that
their conduct [was] lawful.” Davis, 131 S. Ct. at 2427
(internal quotation marks omitted).15 More specifically, the

15
   As the Supreme Court noted in Herring, “good faith
exception” is somewhat of a misnomer. 555 U.S. at 142. The
inquiry is not subjective at all, but instead looks to an
officer‟s “objectively reasonable reliance.” Id. Nonetheless,




                             35
Supreme Court has held this exception to cover situations
where law enforcement personnel have acted in objectively
reasonable reliance on some seemingly immutable authority
or information that justifies their course of action. See Davis,

 (later-reversed binding appellate precedent);
Herring, 

 (undiscovered error in police-
maintained database); Arizona v. Evans, 

 (1995)
(undiscovered error in court-maintained database); Illinois v.
Krull, 

 (1987) (subsequently overturned statute);
United States v. Leon, 

 (1984) (later-invalidated
warrant).

       To determine whether a particular situation is covered
under this good faith exception, the Supreme Court has
directed courts to consider whether exclusion would serve “to
deter future Fourth Amendment violations.” Davis, 131 S.
Ct. at 2426; see also Leon, 468 U.S. at 918 (“If exclusion of
evidence obtained pursuant to a subsequently invalidated
warrant is to have any deterrent effect, . . . it must alter the
behavior of individual law enforcement officers or the
policies of their departments.”). Thus, in analyzing whether
the good faith exception applies, the Court balances “the
benefits of the rule‟s deterrent effects against the costs of
exclusion, which include „letting guilty and possibly
dangerous defendants go free.‟” United States v. Tracey, 

, 151 (3d Cir. 2010) (quoting Herring, 555 U.S. at
141).

     When considering the benefits gained from deterrence,
we must necessarily consider the nature and culpability of the

because the Supreme Court (and our own decisions) use the
terms interchangeably, we do so as well.




                              36
police conduct at issue. As the Supreme Court has explained,
“police conduct must be sufficiently deliberate that exclusion
can meaningfully deter it, and sufficiently culpable that such
deterrence is worth the price paid by the justice system.”
Herring, 555 U.S. at 144; Davis, 131 S. Ct. at 2429
(cautioning courts not to discourage “the officer from doing
his duty” (alteration and internal quotation marks omitted)).
Thus, “we apply the rule when police conduct is „deliberate,
reckless, or grossly negligent,‟ or when it will deter „recurring
or systemic negligence.‟” Tracey, 597 F.3d at 151 (quoting
Herring, 555 U.S. at 144). On the other hand, isolated or
attenuated acts of negligence do not warrant the rule‟s
application. Id.

       In light of these principles, the Government argues that
the police conduct at issue in this case does not rise to the
level of culpability necessary for the exclusionary rule to
apply and that, as a consequence, the balancing test outlined
in Herring and Davis militates in favor of applying the good
faith exception. In service of its argument, the Government
urges that the police acted with an objectively reasonable
good faith belief that their conduct was constitutional because
“[b]efore Jones, every court of appeals to consider the
question[, with the exception of one,] had concluded that, in
light of the Supreme Court‟s decision in [Knotts], police did
not need to obtain a warrant to install a GPS tracking device
on the exterior of a vehicle or to use that device to monitor
the vehicle‟s movements on public roads.” (Appellant Br. at
48-49.) Indeed, the Government posits that this “consensus”
among our sister circuits, coupled with the “guidance in
Knotts and Katz,” absolves law enforcement personnel for
purposes of the exclusionary rule. (Id. at 50, 55 n.21; Oral
Argument Tr. at 23.) We find the Government‟s position




                               37
unpersuasive and therefore hold that the good faith exception
does not apply here.

B.   Reliance on Beeper Cases

       The Government posits that law enforcement
personnel acted in good faith because they relied on, among
other things, the Supreme Court‟s “guidance” from Knotts
that using an electronic tracking device does not violate the
Fourth Amendment. (Appellant Br. at 55 n.21.) Indeed, the
Government observes that the reasoning from Knotts
underpins the decision of “every court of appeals to consider”
GPS tracking (save the D.C. Circuit). (Id. at 48-49.) We first
ask ourselves, therefore, whether the Knotts decision — along
with its sibling case, Karo — qualifies as binding precedent
under Davis v. United States, wherein the Supreme Court held
that the good faith exception covers police officers acting in
reliance on later-invalidated binding appellate precedent. 

. As the forthcoming discussion demonstrates, we
find that the explicit holding from Davis is inapposite because
Knotts and Karo are both distinguishable given (1) the lack of
a physical intrusion in those cases, (2) the placement by
police of the beepers inside containers, and (3) the marked
technological differences between beepers and GPS trackers.

       In Davis, the police had executed a search of the
defendant‟s car subsequent to his arrest. At the time of the
search, prevailing Supreme Court and Eleventh Circuit
precedent held that the police could lawfully search a
suspect‟s car incident to his arrest. See New York v. Belton,

 (1981); United States v. Gonzalez, 

(11th Cir. 1996). The defendant unsuccessfully challenged
the search. While the defendant‟s appeal was pending, the
Supreme Court limited Belton, effectively restricting the areas




                              38
of the car that the police were allowed to search after a
suspect‟s arrest. See Arizona v. Gant, 

 (2009).
In deciding Davis, the Supreme Court reasoned that
“[r]esponsible law-enforcement officers will take care to learn
what is required of them under Fourth Amendment precedent
and will conform their conduct to these rules.” 131 S. Ct. at
2429 (internal quotation marks omitted). According to the
Court, the police in Davis merely behaved as “reasonable
officer[s] would and should act.” Id. (internal quotation
marks omitted). Consequently, the Court found that “[t]he
deterrent effect of exclusion in such a case can only be to
discourage the officer from do[ing] his duty,” which was not
“the kind of deterrence the exclusionary rule seeks to foster.”
Id. (internal quotation marks omitted). Ultimately, therefore,
the Court deemed that the police in Davis were covered by
the good faith exception to the exclusionary rule and evidence
recovered pursuant to the search was not suppressed. Id.

       Of great significance to the instant case is the fact that
in Davis the police relied on binding appellate precedent that
“specifically authorize[d the] particular police practice.” Id.
at 2429 (first emphasis added). Indeed, as Justice Sotomayor
noted in her concurrence, Davis did not “present the markedly
different question whether the exclusionary rule applies when
the law governing the constitutionality of a particular search
is unsettled.” Id. at 2435 (Sotomayor, J., concurring).16 By

16
   We also note that the Eleventh Circuit‟s opinion in Davis
was explicit on this point: “[We refuse] to apply the
exclusionary rule when the police have reasonably relied on
clear and well-settled precedent. We stress, however, that
our precedent on a given point must be unequivocal before
we will suspend the exclusionary rule‟s operation.” United




                               39
its plain terms, therefore, the express holding in Davis is
inapposite to this case because Knotts and Karo do not
qualify as appropriate binding appellate precedent: Neither
case involved a physical trespass onto the target vehicle; in
both cases the police placed the beeper inside of a container
which was then loaded into the target vehicle by the driver
(all with the container owner‟s permission). See Karo, 468
U.S. at 708; Knotts, 460 U.S. at 278. Additionally, both Karo
and Knotts addressed the use of beepers, which — as we have
already explained — are markedly different from GPS
trackers. See Maynard, 615 F.3d at 556-57.

       Davis extends good faith protection only to acts that
are explicitly sanctioned by clear and well-settled precedent,
and neither Knotts nor Karo sanction the type of intrusion at
issue in this case.      Consequently, we hold that law
enforcement‟s reliance on the beeper cases, standing on its
own, cannot sufficiently insulates the GPS search in this case
from the exclusionary rule.

States v. Davis, 

, 1266 (11th Cir. 2010)
(citations omitted) (emphasis added); see also United States v.
Buford, 

, 276 n.9 (6th Cir. 2011) (“Like the
Eleventh Circuit, we also „stress, however, that our precedent
on a given point must be unequivocal before we will suspend
the exclusionary rule‟s operation.‟” (quoting Davis, 598 F.3d
at 1266)); United States v. McCane, 

, 1045 n.6
(10th Cir. 2009) (finding that the good faith exception applied
because “Tenth Circuit jurisprudence supporting the search
was settled. Thus, there was no risk that law enforcement
officers would engage in the type of complex legal research
and analysis better left to the judiciary and members of the
bar”).




                              40
C.   Reliance on Out-of-Circuit GPS Cases

        We therefore consider the Government‟s contention
that the good faith exception applies because the police acted
in objectively reasonable reliance on out-of-circuit precedent
sanctioning warrantless GPS surveillance. (Appellant Br. at
15-16 (“Before [Jones], all but one of the courts of appeals to
have addressed the issue had approved the warrantless
installation and monitoring of a GPS device on a vehicle. . . .
[T]he agents‟ reliance on this body of case law was
objectively reasonable . . . .”).) And while the Government
relies, in no small part, on the reasoning in Davis for support,
we think that reading Davis so broadly would strain its
reasoning, to say nothing of its holding.17




17
  We note that the majority in Davis itself suggested that its
holding is inapplicable to the situation presented in this case.
While explaining that its ruling will not deter defendants from
challenging existing Fourth Amendment doctrine, the
Supreme Court noted:

This Court reviews criminal convictions from 12 Federal
Courts of Appeals, 50 state courts of last resort, and the
District of Columbia Court of Appeals. If one or even many
of these courts uphold a particular type of search or seizure,
defendants in jurisdictions in which the question remains
open will still have an undiminished incentive to litigate the
issue.    This Court can then grant certiorari, and the
development of Fourth Amendment law will in no way be
stunted.




                              41
       The Davis decision hinged on the understanding that
“[r]esponsible law-enforcement officers will take care to learn
what is required of them under Fourth Amendment precedent
and will conform their conduct to these rules.” Id. (internal
quotation marks omitted). At the most basic level, then, the
applicable body of “Fourth Amendment precedent” to which
the responsible officer must conform consists of those
decisions that are binding on the officer‟s jurisdiction.
Accord Hudson v. Michigan, 

, 599 (2006)
(noting that officers are expected to learn and abide by “what
is required of them” by courts having jurisdiction over them).

        Thus, as already stated, the Court in Davis recognized
that the good faith exception applies to situations where the
police “conducted a search in objectively reasonable reliance
on binding appellate precedent,” 131 S. Ct. at 2434, because
“[t]he deterrent effect . . . in such a case can only be to
discourage the officer from do[ing] his duty,” which was not
“the kind of deterrence the exclusionary rule seeks to foster,”
id. at 2429 (internal quotation marks omitted). The same
cannot be said where the law is unsettled in a particular
jurisdiction, even where persuasive authority may exist in the
form of decisions by other circuit courts.

       Indeed, extending the rationale from Davis to cover
reliance on out-of-circuit precedent would turn this principle
on its head: Though our first and last word on the matter is
that warrantless GPS searches are unconstitutional, in effect
the Government argues that our sister circuits‟ decisions

Davis, 131 S. Ct. at 2433 (emphasis added) (footnote
omitted). Thus, the Court in Davis recognized that its holding
was limited to jurisdictions where the law was clearly settled.




                              42
should control whether the evidence is excluded. This rule
would eviscerate the notion that clear and well-settled
precedent should control and thus contradicts the basic
principles of stare decisis. We respect our sister circuits, but
their decisions cannot dictate our conclusions. As such, any
law enforcement officer who acts primarily in reliance on the
Fourth Amendment proclamations of our sister circuits does
so at his own peril for purposes of the exclusionary rule.

        This is particularly true where, as in this case, our
sister circuits are split on the relevant issue. The GPS search
of Harry Katzin‟s van occurred in late 2010. By that time,
four of our sister circuits — the Seventh, Eighth, Ninth, and
D.C. Circuits — had addressed GPS surveillance. Of those,
three circuits had held that GPS surveillance either did not
constitute a search or, even if it did, that the police did not
require a warrant. See McIver, 

; Garcia, 

; Pineda-Moreno, 

; Marquez, 

.

       At the same time, the D.C. Circuit had held in United
States v. Maynard (which became Jones on appeal to the
Supreme Court) that GPS surveillance did constitute a search
and that the police did require a warrant. Maynard, 

. At bottom, then, the Government seems to argue that
reliance on a majority of a minority of our sister circuits is
sufficient to escape the exclusionary rule. This cannot be.
Although we find it commendable that law enforcement
personnel would take the time to pore over out-of-circuit
decisions relating to police procedures, it is not their duty for
purposes of the exclusionary rule to parse and weigh the
decisions of our sister circuits in an attempt to predict what




                               43
this Court (or even the Supreme Court) would say if faced
with a similar case.18



18
   The Government urges that our analysis in United States v.
Duka, 

, 347 (3d Cir. 2011) (addressing evidence
obtained in a search pursuant to the Foreign Intelligent
Surveillance Act (FISA)), supports the proposition that the
reasoning from Davis is not limited to binding precedent.
(Appellant Br. at 61-62 (“[The] insistence on binding
authority does not accord with this Court‟s approach
following Davis. . . . [Duka] undermines the district court‟s
position that reliance on non-binding case law . . . is per se
unreasonable.”).) This is not correct. Not only was the good
faith discussion in Duka based on a different Supreme Court
decision — Krull, which addressed objectively reasonable
reliance on a later-invalidated statute — but the entire
discussion of the good faith exception is dicta. See Duka, 671
F.3d at 346 (discussing the “good faith” exception only after
noting that “[w]e are confident that FISA‟s „significant
purpose‟ test satisfies the Fourth Amendment”). Moreover,
the Government‟s argument seems to hinge on a footnote that
contains the opinion‟s lone citation to Davis. In that footnote,
this Court stated that “[t]he objective reasonableness of the
officers‟ reliance on the statute in this case is further bolstered
by the fact that the particular provision at issue has been
reviewed and declared constitutional by several courts, going
as far back as 2002.” Id. at 347 n.12 (collecting cases). Since
none of these “several courts” are the Third Circuit, the
Government argues, Duka demonstrates our willingness to
apply the rationale from Davis to non-binding authority. We
think this makes a mountain out of a molehill: this single




                                44
       Moreover, we cannot burden district courts with the
type of case-by-case assessment that the Government‟s
position would require. Unlike the archetypal situations in
Leon or Davis, finding that the good faith exception applies in
this case would, of necessity, require courts ruling on
suppression motions to discern what amounts to sufficient
out-of-circuit authority for purposes of an objectively
reasonable good faith belief. Thus, district courts would need
to consider how many circuits had addressed the police
practice in question, what each one had said, whether the
statements were mere dicta, and myriad other factors. Such
an approach has no limiting principle and defies rational
application. Surely police reliance on a single out-of-circuit
decision could not support good faith, but what about two? If
the circuits split two-to-one, that would present yet another
problem. And what if our sister courts had all ruled in near-
unanimity on a point, with one stalwart (perhaps, highly
persuasive) holdout? Is the presence of good faith to be
decided with an abacus or does the strength of each court‟s
argument bear consideration? Because we foresee that it
could lead to a sprawling, amorphous, and self-contradicting
doctrine, we decline to adopt the Government‟s position and
hold that reliance on out-of-circuit precedent (even where
there is a so-called “consensus”) cannot, in and of itself,
support application of the good faith exception.19


reference to Davis comes in dicta, in a footnote, as part of a
“cf.” citation.
19
   To see just how unwieldy the analysis could be, we need
look no further than the Government‟s own arguments in this
case. At oral argument, the Government attempted to
minimize the significance of Maynard, suggesting that this




                              45
D.   Exclusion based on Culpability and Deterrence

       Up to this point we have considered only whether
reliance by law enforcement personnel on out-of-circuit or
distinguishable authority, by itself, suffices for purposes of
the good faith exception. Per the previous discussion, we
hold that such reliance is insufficient to support a per se
finding of good faith.20 The Supreme Court in Herring and

single decision had come too late in the process and was,
ultimately, distinguishable.      Such arguments would be
disastrously disruptive to lower courts if we were to hold that
reliance on out-of-circuit authority could, by itself, suffice for
purposes of the good faith exception. How up-to-date must
law enforcement be regarding the state of relevant legal
principles? What if a decision were issued but either (a) was
late in being added to a reporter/electronic database or (b) did
not get sufficiently wide-spread exposure to bring it to the
attention of police departments half-way across the country?
Not only would district courts be forced to tally the
authorities on either side of an issue like so many chit marks,
but they would also have to decide whether decisions had
come too late, or were perhaps too obscure.
20
   We note that some of our sister circuits have ruled
otherwise, holding that, per Davis, pre-Jones warrantless GPS
searches qualify for protection under the good faith exception.
See United States v. Sparks, 

 (1st Cir. 2013);
United States v. Andres, 

 (5th Cir. 2013); United
States v. Pineda-Moreno, 

 (9th Cir. 2012).
These cases, however, do not deter us from our conclusion.

To begin with, all three courts relied on binding precedent
within their own circuits. The Ninth Circuit noted that the




                               46
police could rely on, among other things, McIver for the
proposition that “placing an electronic tracking device on the
undercarriage of a car was neither a search nor a seizure
under the Fourth Amendment.” Pineda-Moreno, 688 F.3d at
1090. The Fifth Circuit, which devoted a single paragraph to
the discussion, based its conclusion on the presence of
Michael, and its holding that “„reasonable suspicion is
adequate to support warrantless beeper installation‟ on a
suspect‟s vehicle parked in a public space.” Andres, 703 F.3d
at 835 (quoting Michael, 645 F.2d at 257). Finally, the First
Circuit based its decision to apply the good faith exception on
the presence of “clear and apposite” authority, including a
First Circuit decision that found “„the lessened expectancy of
privacy associated with motor vehicles justifies the use of
beepers without a warrant to track vehicles . . . only if the
officers have probable cause at the time.‟” Sparks, 711 F.3d
at 65 (quoting United States v. Moore, 

, 112-13
(1st Cir. 1977)). At the same time, however, the First Circuit
was far from certain that out-of-circuit precedent could
support a finding of good faith, noting that “the two appellate
courts to consider the question since Davis have read Davis to
require reliance on the case law of the jurisdiction.” Id. at 63-
64 & 63 n.2 (internal quotation marks omitted).

Moreover, both the First and Fifth Circuits based their good
faith exception determinations on cases dealing with beepers,
with the First Circuit in Sparks going so far as to hold that
Knotts was sufficiently “clear and apposite” so as to support a
finding of good faith. Sparks, 711 F.3d at 65. As our
foregoing discussion suggests: we disagree with this position.
The difference between beepers and GPS trackers is one of
kind, not degree. Any time technology shifts in this way,




                               47
Davis, however, recognized that the good faith exception
inquiry requires more. That is, in determining whether law
enforcement personnel acted “with an objectively „reasonable
good-faith belief‟ that their conduct [was] lawful,” we must
consider whether the totality of circumstances is greater than
the sum of its attendant parts. See Davis, 131 S. Ct. at 2427
(quoting Leon, 468 U.S. at 909). We therefore undertake the
balancing test outlined in Herring and Davis, and ask whether
— in light of all the circumstances — the police activity in
this case rises to the level of a “deliberate, reckless, or grossly
negligent” violation of the Fourth Amendment. See Herring,
555 U.S. at 144; Tracey, 597 F.3d at 151. We hold that it
does.

       Per the Government‟s argument, the legal landscape in
this case predominantly consisted of the out-of-circuit GPS
cases, the Supreme Court‟s beeper decisions, and the
overarching privacy expectation framework for Fourth
Amendment analysis adopted in Katz and deemed to be the
sole rubric for analysis until Jones.21 (See, e.g., Appellant Br.

courts should expect that law enforcement will tread lightly
and will refrain from reasoning by (potentially ill-fitting)
analogy. Cf. Kyllo v. United States, 

, 35-36
(2001) (discussing the Court‟s reticence to “leave the
homeowner at the mercy of advancing technology”).
21
   Our dissenting colleague points to a number of other
decisions and Fourth Amendment doctrines which add further
sauce to the Government‟s good faith goose. (See Dissent at
20-29 (discussing, for example, privacy considerations in the
exterior of an automobile).) While we do not disagree that
these too were part of the relevant legal landscape at the time
the police executed their search, we nevertheless hold that —




                                48
at 44, 50, 55 n.21; Oral Argument Tr. at 23.) Taken together,
the Government contends, these sources of legal authority
would lead a reasonable law enforcement officer to conclude
that he was acting within the confines of the constitution
when attaching a GPS tracker to the undercarriage of Harry
Katzin‟s van. We find that, on balance, this collection of
authority does not warrant applying the good faith exception.
Try as we might to allay our concerns, we remain supremely
discomfited by the lack of binding appellate guidance
underlying the police action at issue in this case. Therefore,
we hold that the police acted with sufficient constitutional
culpability to require exclusion and, more importantly, that
suppression in this case would help deter future Fourth
Amendment violations.

       Law enforcement personnel can rightly rely on a
number of sources for Fourth Amendment guidance —
including on-point decisions by the Supreme Court and this
Circuit, warrants, and statutes. We, both as a Court and as a
society, expect that law enforcement officers will consult

in light of our forthcoming discussion — such authority gets
further and further afield of the relevant police conduct and
could only supply marginal support to justify the police
action.

       The only possible exception is the advisory
commentary on Federal Rule of Criminal Procedure 41.
(Dissent at 32.) However, for the reasons articulated below,
see infra note 24, we find that this commentary would not
help the Government‟s position — even assuming the
Government had seen fit to cite (let alone mention) the
language in its briefs or at oral argument.




                             49
these sources — it is a part of how we expect reasonable
officers to act. Davis, 131 S. Ct. at 2429. Deterring such
activity, therefore, would not serve the purposes of the
exclusionary rule. Id. This case, as we have just mentioned,
is different. Nothing in a law enforcement officer‟s duties
forces him to either rely on non-binding precedent or to
conduct the Fourth Amendment calculus himself by
extrapolating from, or analogizing to, existing case law.
Where an officer decides to take the Fourth Amendment
inquiry into his own hands, rather than to seek a warrant from
a neutral magistrate — particularly where the law is as far
from settled as it was in this case — he acts in a
constitutionally reckless fashion.

       Here, law enforcement personnel made a deliberate
decision to forego securing a warrant before attaching a GPS
device directly to a target vehicle in the absence of binding
Fourth Amendment precedent authorizing such a practice.
Indeed, the police embarked on a long-term surveillance
project using technology that allowed them to monitor a
target vehicle‟s movements using only a laptop, all before
either this Circuit or the Supreme Court had spoken on the
constitutional propriety of such an endeavor. (That the
surveillance lasted only a few days is mere coincidence.22)

22
    We therefore reject the Government‟s attempts to
distinguish Maynard. While it is true that the surveillance in
Maynard lasted for nearly a month as compared to the several
days in this case, it remains equally true that when the police
attached their GPS device to Harry Katzin‟s van, they had no
way of knowing when the next Rite Aid robbery would take
place. We likewise disagree with our Dissenting colleague‟s
assessment of Maynard. (Dissent at 29-31.) The good faith




                              50
True, the police did not act in a total vacuum, but their chosen
course of action when presented with such a novel
constitutional situation is nonetheless troubling: In lieu of a
binding proclamation from either this Circuit or the Supreme
Court — and instead of seeking approval from a neutral
magistrate — law enforcement personnel looked to other
(non-binding or distinguishable) authorities like our sister
circuits‟ decisions. Essentially, they extrapolated their own
constitutional rule and applied it to this case. We fail to see
how this absolves their behavior. The assumption by law
enforcement personnel that their own self-derived rule
sanctioned their conduct — to say nothing of their unstated
belief that this Circuit would automatically side with a
majority of the minority of our sister circuits — was
constitutionally culpable.23


exception analysis cannot be post-hoc, and the police action
at issue must be analyzed under the circumstances as they
existed at the time the action was taken — in this case, before
the police knew when their GPS surveillance would end.
23
   The Government suggests that the good faith exception
should apply because the police sought confirmation from
“experienced government attorneys.” (Appellant Br. at 56.)
The Government cites Messerschmidt v. Millender, 

 (2012), for the proposition that it shows good faith on
the part of an officer if he obtains “approval of the warrant
application from a superior and a prosecutor before
submitting it to a magistrate.” (Appellant Br. at 57.)
However, Messerschmidt is inapposite. That case considered
good faith in the context of an officer relying on a warrant
that had been based on an allegedly paltry affidavit. Thus, the
opinion of a third party tended to demonstrate that the officer




                              51
        The decisions in Knotts and Katz do not remedy the
situation. The Government suggests that in this case law
enforcement personnel properly reasoned that the GPS search
did not require a warrant by analogizing to Knotts‟ discussion
of electronic tracking devices. Doing so, the Government
adds, was imminently reasonable given the prevailing Fourth
Amendment framework at the time — the privacy theory
from Katz. That is, the Government contends that because
law enforcement personnel were aware that a search occurs
when the police intrude upon a target‟s reasonable
expectation of privacy, they acted in good faith by relying on
our sister circuits‟ GPS decisions as well as Knotts‟ statement
that, among other things, “[a] person travelling in an
automobile on public thoroughfares has no reasonable
expectation of privacy in his movements from one place to
another.” Knotts, 460 U.S. at 281. We find such reasoning


had not acted with knowledge of the affidavit‟s deficiency. In
the instant case, the police lack even an affidavit. Moreover,
a government attorney‟s approval, standing alone, cannot and
should not suffice to demonstrate good faith. Cf. Leon, 468
U.S. at 914 (“[T]he courts must also insist that the magistrate
purport to perform his neutral and detached function and not
serve merely as a rubber stamp for the police. . . . [A
magistrate] who acts instead as an adjunct law enforcement
officer cannot provide valid authorization for an otherwise
unconstitutional search.” (internal quotation marks omitted)).
Thus, while we agree that it is another “factor to consider,”
(Oral Argument Tr. at 51-52; Dissent at 33), we nonetheless
hold that, in this case, seeking the advice of a “government
attorney[]” does not offer much support to the Government‟s
position.




                              52
dangerous for the reasons already articulated above: Law
enforcement can always derive some constitutional principle
from existing decisions — which is particularly true when
they also look directly to a generalized baseline case like
Katz. It cannot be that the good faith exception applies in
every instance when the police act in reliance on such a self-
derived principle. If it did, then all Fourth Amendment
protections would be rendered ineffective — the police could
intrude upon anyone‟s Fourth Amendment rights without fear
of suppression merely by relying on a particularly broad-
sweeping, self-derived constitutional principle. We fear that
accepting the Government‟s position, in effect, would lead to
the good faith exception swallowing the exclusionary rule.24


24
   The Dissent argues that Federal Rule of Criminal Procedure
41 — particularly the 2006 advisory committee notes to that
rule — further supports a finding that the law enforcement
officers in this case acted with an objectively good faith belief
that their conduct was constitutional. (Dissent at 32.) In
particular, the Dissent points to the following language from
the 2006 advisory committee notes: “If . . . the officers intend
to install and use [a tracking device] without implicating any
Fourth Amendment rights, there is no need to obtain a
warrant.” Fed. R. Crim. P. 41(b) advisory committee‟s note
(2006) (citing Knotts, 

). This language,
however, stands for nothing more than the unremarkable
proposition that the police need not obtain a warrant if their
action does not violate the Fourth Amendment. Without our
(or the Supreme Court‟s) having ruled on the matter,
however, the police could not reasonably say that the use of a
GPS tracker would not “implicat[e] . . . Fourth Amendment
rights.” Indeed, even under the most generous rationale, this




                               53
       Moreover, since such constitutionally reckless action
was the Government‟s default choice in this case, we hold
that applying the exclusionary rule aptly serves its intended
purpose: to “deter future Fourth Amendment violations.”
Davis, 131 S. Ct. at 2426; see also id. at 2435 (Sotomayor, J.,
concurring) (“[W]hen police decide to conduct a search or
seizure in the absence of case law (or other authority)
specifically sanctioning such action, exclusion of the
evidence obtained may deter Fourth Amendment
violations . . . .”). The police practice at issue here effectively
disregarded the possibility that we could find a GPS search to
constitute a Fourth Amendment violation requiring a warrant.
But a Fourth Amendment violation is a Fourth Amendment
violation. While the police may feel free to act with
impunity, confident in the illusory protection of non-binding
precedent, each search could still be violating the
Constitution. Thus, where we have not yet ruled on the
constitutionality of a police tactic, law enforcement personnel
have two choices: (a) assume that their conduct violates the
Fourth Amendment and that we will require them to obtain a
warrant, or (b) gamble, at the risk of having evidence
excluded, that we will find no Fourth Amendment violation in


language could only have favored the Government‟s
argument if the GPS search occurred prior to the Maynard
decision (i.e., before any circuit had suggested that GPS
searches violated the Fourth Amendment). However, once
the circuits split on the issue of whether using a GPS tracker
constitutes a search, law enforcement officials were on notice
that such devices could “implicat[e] . . . Fourth Amendment
rights” and the commentary became borderline irrelevant for
good faith purposes.




                                54
a particular situation.25 This is in line with the Supreme
Court‟s suggestion that law enforcement officials should be
incentivized to “err on the side of constitutional behavior.”
United States v. Johnson, 

, 561 (1982).26
25
   We do not hold, of course, that the police can never make
assumptions about our future Fourth Amendment rulings. We
merely hold that where law enforcement personnel choose to
take the constitutional analysis into their own hands, they
effectively do so without a safety net: If their analysis is
correct and we ultimately affirm the constitutionality of a
search, then the police are rewarded with full use of any
evidence derived from the search. If their analysis is wrong,
however, and the search is ultimately held to be
unconstitutional, then the police cannot avoid the cost of
suppression by relying on the good faith exception. Just as
the police enjoy the benefits when they are correct, so, too, do
they bear the costs when they are wrong. Of course, the
police can avoid this entire issue by requesting a warrant in
the first instance.
26
    Johnson addressed retroactive application of Fourth
Amendment decisions. In discussing the matter, the Court
stated:

If, as the Government argues, all rulings resolving unsettled
Fourth Amendment questions should be nonretroactive, then,
in close cases, law enforcement officials would have little
incentive to err on the side of constitutional behavior.
Official awareness of the dubious constitutionality of a
practice would be counterbalanced by official certainty that,
so long as the Fourth Amendment law in the area remained
unsettled, evidence obtained through the questionable practice
would be excluded only in the one case definitively resolving




                              55
Excluding the evidence in this case would incentivize just that
and would therefore result in “appreciable deterrence” of
future Fourth Amendment violations. Leon, 468 U.S. at 909
(internal quotation marks omitted).

        Thus, heeding the Supreme Court‟s views in Herring
and Davis, and after considering the Government‟s various
arguments, we find that the “deterrent effect of suppression
[in this case is] substantial and outweigh[s] any harm to the
justice system.” Herring, 555 U.S. at 147. The police acted
in the face of unsettled law at a time when courts were
becoming more attuned to the argument that warrantless GPS
surveillance violated the Fourth Amendment. Excluding the
evidence here will incentivize the police to err on the side of
constitutional behavior and help prevent future Fourth
Amendment violations. We therefore conclude that the police
actions taken here do not qualify under the good faith
exception and hold that the exclusionary rule should apply in
this case.27


the unsettled question. Failure to accord any retroactive
effect to Fourth Amendment rulings would encourage police
or other courts to disregard the plain purport of our decisions
and to adopt a let‟s-wait-until-it‟s-decided approach.

Johnson, 457 U.S. at 561 (footnote and internal quotation
marks omitted).
27
   It bears noting that we do not deal here with a situation
where some on-point binding precedent exists. That is, we
are not presented with a case wherein law enforcement
personnel were asked to apply on-point binding appellate law
to a new factual scenario. Indeed, we recognize that applying




                              56
V.   STANDING AND THE KATZIN BROTHERS

       Fourth Amendment rights are personal rights, and a
defendant seeking to suppress evidence must therefore
demonstrate a violation of his own Fourth Amendment rights
before he can be granted any form of relief. See Minnesota v.
Carter, 

, 88 (1998); United States v. Mosley, 

, 253 (3d Cir. 2006). Thus, having held that the
District Court rightly suppressed the evidence found in Harry
Katzin‟s van, we must now consider whether all three of the
brothers had standing to challenge the admissibility of this
evidence. The Government would have us divide the stop
into two distinct incidents: (1) the stop of Harry Katzin and
(2) the stop of Mark and Michael Katzin, with each stop
presenting a different constitutional situation. For the reasons
discussed below, we hold that the stop of Harry Katzin‟s van
must be treated as a single incident implicating the Fourth
Amendment rights of all three brothers and, consequently, we
find that all three had standing.


existing precedential frameworks to subtle factual
permutations is something that police officers — and other
law enforcement personnel — do all the time. We have no
occasion (or desire) to curtail such practices in this opinion.
Thus, for example, we do not purport to limit the ability of an
officer to decide whether a particular situation gives rise to
exigent circumstances while standing outside an apartment
door with suspicious sounds emanating from within. Such a
case could lead to a different outcome under the Herring and
Davis balancing test given that, unlike here, the officer would
not be leaping recklessly into an unexplored constitutional
situation.




                              57
       We begin by stating the obvious: There is not, nor can
there be, any dispute as to whether Harry Katzin — as the
owner of the van — has standing to challenge the
constitutionality of the GPS search as well as the stop and
subsequent search of his van, and to seek suppression of any
evidence discovered within the vehicle.         Indeed, the
Government concedes as much. (Appellant Br. at 69.)
Certainly, then, the District Court rightly suppressed the
evidence as against Harry Katzin.

        The Government does challenge the standing of Mark
and Michael Katzin. (Id. at 67-74.) Since “a search of a car
does not implicate the rights of non-owner passengers,” the
Government contends that such passengers are “generally
held to lack „standing‟ to object to evidence discovered in a
search of a vehicle.” Mosley, 454 F.3d at 253 (citing Rakas v.
Illinois, 

, 147 (1978)). This much is true.
However, we have also held that “when a vehicle is illegally
stopped by the police, no evidence found during the stop may
be used by the government against any occupant of the
vehicle unless the government can show that the taint of the
illegal stop was purged.” Id. at 251.28

28
    We explicitly noted in Mosley that courts “should not be
distracted by the fact that this case involves evidence found in
a car.” Mosley, 454 F.3d at 253. As Mosley explained, the
constitutional violation stems not from the “search of the car .
. . [but] the seizure of [the passenger].” Id. at 253 & n.6 (“[A]
Fourth Amendment seizure of every occupant occurs the
moment that vehicle is pulled over by the police.”) The same
is true of the case at bar: while the police did search Harry
Katzin‟s van, this was done only after pulling the van to the
side of the road, thereby “seizing” all three brothers.




                               58
        This Court in United States v. Mosley considered the
illegal stop and subsequent search of a vehicle carrying three
individuals, during the course of which the police discovered
several firearms from the car. We held that the stop and
subsequent search of the car was to be treated as a single
event, thereby rejecting an approach that would split the
inquiry between several “individual constitutional violations,
each with [its own] victim, each of whom may seek to
suppress only the fruits of the violation of his individual
rights.” Id. at 257-58. In part, this conclusion was
occasioned by our holding that “[t]he relationship between
the seizure of a passenger in a moving vehicle, which
necessarily occurs when that vehicle is stopped by the police,
and the subsequent discovery of evidence during that stop, is
one of ineluctable and undeniable correlation.” Id. at 266.
Additionally, while we acknowledged that “Fourth
Amendment rights are personal rights,” we also expressly
rejected “blind adherence to a phrase which at most has
superficial clarity and which conceals underneath that thin
veneer all of the problems of line drawing which must be
faced in any conscientious effort to apply the Fourth
Amendment.” Id. at 267 (quoting Rakas, 439 U.S. at 147).
In light of our decision in Mosley, Mark and Michael Katzin
argue that they have standing to challenge the admissibility of
evidence seized from Harry Katzin‟s van by virtue of being
subjected to an illegal stop that thereby rendered any evidence
discovered in Harry Katzin‟s van fruit of the poisonous tree.
Id. at 256 (“Where the traffic stop itself is illegal, it is simply
impossible for the police to obtain the challenged evidence
without violating the passenger‟s Fourth Amendment rights.”)
We agree.29

29
     It bears noting that Mark and Michael Katzin challenge the




                                59
       True, precedent exists to support the proposition that
an individual cannot challenge the legality of a search which
was executed based on information obtained as a
consequence of some illegal search or seizure of a third party.
See, e.g., United States v. Chase, 

, 70-71 (9th Cir.
1982).     Such holdings are premised on the principle
underlying the Government‟s position: Fourth Amendment
rights “are personal and may be enforced by exclusion of
evidence only by one whose own legal rights and interests
were infringed by the search and seizure.” Id. (discussing
Rakas v. Illinois, 

). The presence of Mosley,
however, alters this analysis.

        The Government effectively contends that we must
treat the stop of Harry Katzin‟s van as constituting two stops:
The first, a stop (i.e., seizure) of Harry Katzin himself as a
result of the GPS search. The second, a stop of Mark and
Michael Katzin based on the probable cause developed
through use of information derived from the GPS search. The
Government would have us evaluate the legality and
attendant Fourth Amendment consequences (if any) of each
stop individually. We rejected this individualized approach in
Mosley, holding instead that “an illegal traffic stop of a car
occupied by a driver and a passenger [constitutes] a single
constitutional violation, with [multiple] victims, each of
whom can seek to suppress all fruits of that violation.”
Mosley, 454 F.3d at 257-58; id. at 267 (“It defies common

stop of Harry Katzin‟s van, not the GPS search itself. That in
the course of challenging the stop this Court must necessarily
consider the constitutionality of the GPS search is merely
incidental: Mark and Michael seek to vindicate their own
rights, not those of their brother.




                              60
sense and common experience to transmute one action into
three, and we will not endorse a Fourth Amendment approach
that relies on such a transmutation.”) In effect, then, the
illegality of the stop as it related to Harry Katzin is extended
to his brothers (passengers). Consequently, we hold that
Mark and Michael had standing to contest the stop and that
the District Court rightly suppressed the evidence as to all
three brothers.

VI.   CONCLUSION

       For the reasons discussed above, we will affirm the
District Court‟s suppression of evidence discovered inside of
Harry Katzin‟s van.




                              61
VAN ANTWERPEN, Circuit Judge, concurring in part and
dissenting in part.

       To briefly recap: In December 2010, law enforcement
officers, after consulting an Assistant United States Attorney,
and in accord with the general policy of the United States
Department of Justice, magnetically attached an
independently battery operated ―slap on‖ Global Positioning
System device (―GPS device‖ or ―GPS‖) upon the
undercarriage of Harry Katzin‘s vehicle, while that vehicle
was parked on a public street. It was conceded at argument
that the officers had probable cause to do so, although they
did not obtain a warrant. For two days, law enforcement used
that GPS to track the vehicle‘s whereabouts on public roads.
The vehicle never entered a private garage, never entered the
curtilage of a home, nor did it enter a similarly private area.
The information from that GPS then led to the seizure of
evidence and the arrest of Harry Katzin and his two brothers,
due to their involvement in a major ongoing scheme to steal
drugs from Rite Aid pharmacies.

        At that time, the Supreme Court, in cases involving
electronic beepers in vehicles, had held that ―[a] person
traveling in an automobile on public thoroughfares has no
reasonable expectation of privacy in his movements from one
place to another.‖ United States v. Knotts, 

, 281
(1983); see also United States v. Karo, 

, 713–16
(1984). All but one of the United States Court of Appeals to
have addressed the issue, in light of Knotts, Karo, and other
general Fourth Amendment principles, held that GPS or
similar electronic surveillance (―GPS-like device‖ or ―GPS-
like‖) could be conducted in the same way that occurred here:
without an authorizing warrant. This view was reflected in




                              1
then-current Rule 41(b) of the Federal Rules of Criminal
Procedure, the commentary to which stated that a warrant was
not required to conduct electronic vehicle surveillance ―[i]f . .
. the officers intend to install and use [an electronic
surveillance] device without implicating any Fourth
Amendment rights.‖ FED. R. CRIM. P. 41(b) advisory comm.
note (2006). No decision from our Circuit was on point.
Then came United States v. Jones, 

__, 

 (2012).

       In light of the Supreme Court‘s decision in Jones, and
for the reasons discussed in the majority opinion, I agree that
the Fourth Amendment now requires law enforcement
officers to obtain a warrant, issued upon probable cause,
before they install a GPS or a GPS-like device on a person‘s
automobile, or other mobile property, and thereafter use that
device to conduct continuing surveillance. See Majority
Opinion (―Maj. Op.‖) at 18.1

       I disagree, however, with the majority‘s conclusion
that the District Court was correct to suppress the evidence
obtained as a result of the warrantless GPS installation and
subsequent surveillance. See Maj. Op. at 34–56. Given pre-
Jones Supreme Court precedent, the consensus regarding
GPS and GPS-like use across the federal courts, and other
relevant considerations, I would hold that the law
enforcement officers here acted ―with an objectively
‗reasonable good-faith belief‘ that their conduct [was]

       1
        I also agree with the majority that, under our decision
in United States v. Mosely, 

 (3d Cir. 2006), each
of the Katzin brothers has standing to seek suppression of the
evidence obtained from Harry Katzin‘s vehicle.




                               2
lawful.‖ Davis v. United States, 

__, 

,
2427 (2011) (quoting United States v. Leon, 

,
909 (1984)). For that reason, suppression in this case is
unwarranted, and I would reverse the District Court.

                              I.

       It is indisputable that the installation and use of the
GPS device in this case was a ―search‖ under the Fourth
Amendment. See Jones, 132 S. Ct. at 949. Furthermore, I
agree with the majority that this particular search now
requires a warrant, and that because the law enforcement
officers here acted without a warrant a violation of the Fourth
Amendment occurred.         But ―[t]he fact that a Fourth
Amendment violation occurred . . . does not necessarily mean
that the exclusionary rule applies.‖ Herring v. United States,

, 140 (2009); United States v. Tracey, 

, 151 (3d Cir. 2010). See also Illinois v. Gates, 

, 223 (1983) (―[W]hether the exclusionary rule‘s remedy
is appropriate in a particular context has long been regarded
as an issue separate from the question whether the Fourth
Amendment rights of the party seeking to invoke the rule
were violated by police conduct.‖).

       The exclusionary rule ―is a ‗prudential‘ doctrine,‖
Davis, 131 S. Ct. at 2426 (quoting Pa. Bd. of Probation and
Parole v. Scott, 

, 363 (1998)), utilized to
―compel respect for the constitutional guaranty‖ embodied in
the Fourth Amendment, id. (quoting Elkins v. United States,

, 217 (1960)). See also United States v. Brown,

, 646 (3d Cir. 2011) (―[T]he exclusionary rule is
merely a ‗judicially created remedy designed to safeguard
Fourth Amendment rights generally through its deterrent




                              3
effect.‘‖ (quoting United States v. Calandra, 

,
348 (1974))). Suppression of evidence obtained through a
violation of the Constitution is ―‗not a personal constitutional
right,‘ nor is it designed to ‗redress the injury‘ occasioned by
an unconstitutional search.‖ Davis, 131 S. Ct. at 2426
(quoting Stone v. Powell, 

, 486 (1976)). And
introduction of illegally obtained evidence at trial ―work[s] no
new Fourth Amendment wrong.‖ Calandra, 414 U.S. at 354.
Instead, the exclusionary rule‘s ―sole purpose . . . is to deter
future Fourth Amendment violations.‖ Davis, 131 S. Ct. at
2426.

       But application of the exclusionary rule is not
warranted ―in every circumstance in which it might provide
marginal deterrence.‖ Herring, 555 U.S. at 141 (quoting
Scott, 524 U.S. at 368). Suppression is prudent only where it
would ―result in appreciable deterrence.‖ Leon, 468 U.S. at
909 (emphasis added) (quoting United States v. Janis, 

, 454 (1976)); see also Davis, 131 S. Ct. at 2426–27
(explaining that ―[w]here suppression fails to yield
‗appreciable deterrence,‘ exclusion is ‗clearly unwarranted‘‖
(omission omitted) (quoting Janis, 428 U.S. at 454));
Herring, 555 U.S. at 141 (same); Arizona v. Evans, 

, 11 (1995) (same); Virgin Islands v. John, 

,
417 (3d Cir. 2011) (same). In other words, suppression is
warranted only where its deterrence benefits outweigh the
substantial social costs inherent in ―preclud[ing]
consideration of reliable, probative evidence.‖ Scott, 524
U.S. at 364; see also Davis, 131 S. Ct. at 2427 (―For
exclusion to be appropriate, the deterrence benefits of
suppression must outweigh its heavy costs.‖); Tracey, 597
F.3d at 151 (―To determine whether to apply the rule in a




                               4
particular case, we weigh the benefits of the rule‘s deterrent
effects against the costs of exclusion . . . .‖).

        The costs of suppression are substantial. ―Exclusion
exacts a heavy toll on both the judicial system and society at
large.‖ Davis, 131 S. Ct. at 2427. ―The principal cost of
applying the rule is, of course, letting guilty and possibly
dangerous defendants go free—something that ‗offends basic
concepts of the criminal justice system.‘‖ Herring, 555 U.S.
at 141 (quoting Leon, 468 U.S. at 908). But in addition to its
―costly toll upon truth-seeking and law enforcement
objectives,‖ Scott, 524 U.S. at 364–65 (internal quotation
mark omitted), ―[i]ndiscriminate application of the
exclusionary rule,‖ in some circumstances, ―may well
‗generate disrespect for the law and administration of
justice,‘‖ Leon, 468 U.S. at 908 (alteration omitted) (quoting
Stone, 428 U.S. at 491). Consequently, ―[o]ur cases hold that
society must swallow this bitter pill when necessary, but only
as a ‗last resort.‘‖ Davis, 131 S. Ct. at 2427 (quoting Hudson
v. Michigan, 

, 591 (2006)).

       Against these costs, ―we weigh the benefits of the
rule‘s deterrent effects.‖ Tracey, 597 F.3d at 151. But we
must fight any instinct to ―‗reflexive[ly]‘ appl[y]‖ the rule.
Davis, 131 S. Ct. at 2427 (quoting Evans, 514 U.S. at 13).
The necessary analysis calls for a ―rigorous weighing of [the]
costs and deterrence benefits,‖ focusing primarily ―on the
‗flagrancy of the police misconduct‘ at issue.‖ Id. (quoting
Leon, 468 U.S. at 911). See also John, 654 F.3d at 417
(explaining that the exclusionary rule is ―trigger[ed]‖ only
where police conduct is ―sufficiently deliberate that exclusion
can meaningfully deter it, and sufficiently culpable that such




                              5
deterrence is worth the price paid by the justice system‖
(quoting Herring, 555 U.S. at 144)).

       Of course, ―the deterrence benefits of exclusion ‗vary
with the culpability of the law enforcement conduct‘ at
issue.‖ Davis, 131 S. Ct. at 2427 (alteration omitted) (quoting
Herring, 555 U.S. at 143). On the one hand, ―[w]hen the
police exhibit ‗deliberate,‘ ‗reckless,‘ or ‗grossly negligent‘
disregard for Fourth Amendment rights, the deterrent value of
exclusion is strong and tends to outweigh the resulting costs.‖
Id. (quoting Herring, 555 U.S. at 144); see also John, 654
F.3d at 418 (condoning suppression where police conduct was
―‗deliberate, reckless, or grossly negligent‘‖ (quoting Tracey,
597 F.3d at 151)). But on the other hand, ―when the police
act with an objectively ‗reasonable good-faith belief‘ that
their conduct is lawful, or when their conduct involves only
simple, ‗isolated‘ negligence, the deterrence rationale loses
much of its force, and exclusion cannot ‗pay its way.‘‖ Davis,
131 S. Ct. at 2427–28 (citations and internal quotation marks
omitted) (quoting Herring, 555 U.S. at 137; Leon, 468 U.S. at
909, 908 n.6, 919).

       Under this so-called ―good-faith‖ exception to the
exclusionary rule, beginning with United States v. Leon, the
Supreme Court has consistently ruled that the costs of
suppression are not outweighed by the little, if any, deterrent
benefit of suppressing evidence obtained ―in [a] reasonable
good-faith belief that a search or seizure was in accord with
the Fourth Amendment.‖ Leon, 468 U.S. at 909 (quoting
Gates, 412 U.S. at 255 (White, J., concurring)); see also
Evans, 514 U.S. at 11–12 (―[W]here the officer‘s conduct is
objectively reasonable, excluding the evidence will not
further the ends of the exclusionary rule in any appreciable




                              6
way . . . .‖ (alteration in original) (internal quotation mark
omitted) (quoting Leon, 468 U.S. at 919–20)); Illinois v.
Krull, 

, 348–49 (1987) (―[E]vidence should be
suppressed ‗only if it can be said that the law enforcement
officer had knowledge, or may properly be charged with
knowledge, that the search was unconstitutional under the
Fourth Amendment.‘‖ (quoting United States v. Peltier, 

, 542 (1975))); Leon, 468 U.S. at 922 n.23 (―[O]ur
good faith inquiry is confined to the objectively ascertainable
question whether a reasonably well trained officer would
have known that the search was illegal . . . .‖). Under such
circumstances, ―a reasonable officer cannot have been
expected to know that what he was doing was
unconstitutional,‖ and, as a result, ―he is unlikely to be
discouraged in his actions by the knowledge that the fruits of
his unconstitutional searches will be suppressed.‖ John, 654
F.3d at 417. Thus, at bottom, ―the harsh sanction of exclusion
‗should not be applied to deter objectively reasonable law
enforcement activity.‘‖ Davis, 131 S. Ct. at 2429 (quoting
Leon, 468 U.S. at 919).

                               II.

       Admittedly, the majority posits several pages focused
on the balancing test outlined in Herring and Davis; the test
which I describe at length above. See supra Part I. But while
purporting to consider whether, ―in light of all the
circumstances in this case,‖ the law enforcement officers‘
conduct ―rises to the level of a ‗deliberate, reckless, or grossly
negligent‘ violation of the Fourth Amendment,‖ Maj. Op. at
48, the majority fragments its analysis by discussing whether
Knotts and Karo and the cases from our sister circuits




                                7
addressing GPS and GPS-like devices are ―binding appellate
precedent‖ under Davis.

       Of course, the question of whether Davis‘s specific
holding—that is, that law enforcement reliance on ―binding
appellate precedent‖ qualifies as objective good-faith
conduct—lingers in the background of this case. In the event
the Government were arguing that the law enforcement
officers here relied on ―binding appellate precedent,‖ I would
have no qualms with the majority addressing whether Knotts
and Karo and the relevant cases from our sister courts
properly qualified under that moniker. But, as the majority
makes clear, that is not the Government‘s argument.

        Furthermore, although a seemingly reasonable
analytical choice, the majority‘s decision to first address
whether those cases qualify as ―binding appellate precedent‖
later infects the more general good-faith analysis. That is, the
majority allows its conclusion that the ―Beeper Cases‖ and
the ―Out-of-Circuit GPS Cases‖ are not ―binding appellate
precedent‖ to emaciate the weight given to law enforcement
reliance thereon in the more general good-faith analysis.

       In effect, the majority‘s search for Davis-like ―binding
appellate precedent‖ in this case places a heavy thumb on the
scale in favor of suppression. Such an analysis does not
comply with the Leon line of cases, which, since their
inception, have time and again stated that the touchstone for
the good-faith exception is ―‗the objectively ascertainable
question whether a reasonably well trained officer would
have known that the search was illegal‘ in light of ‗all of the
circumstances,‘‖ Herring, 555 U.S. at 145 (quoting Leon, 468
U.S. at 922 n.23); not whether the officers relied upon




                               8
―binding appellate precedent,‖ or ―some seemingly
immutable authority or information,‖ as the majority implies.
See Maj. Op. at 36; see also id. at 49 (―Try as we might to
allay our concerns, we remain supremely discomfited by the
lack of binding appellate guidance underlying the police
action in this case.‖).

        At bottom, the majority claims that this case is
―different.‖ The officers here acted ―different[ly],‖ (and,
thus, sufficiently culpable so as to justify application of the
exclusionary rule), the majority concludes, because the
officers relied on ―non-binding precedent‖ from our sister
circuits and ―extrapolate[ed] from, or analogiz[ed] to, existing
case law‖ rather than seeking a warrant. Maj. Op. at 50. But
the conclusion that this case is ―different‖ results primarily
from the majority‘s prior determinations that analogous and
non-binding precedent are materially ―different‖ from the
―binding appellate precedent‖ dealt with in Davis; and, thus,
without ―binding appellate precedent,‖ the rationale of Davis
and the other good-faith cases do not apply.

       I do not think this case is ―different‖ from other cases
involving the good-faith exception, where courts are
presented with specific facts and particularities and then
asked whether ―a reasonably well trained officer would have
known that the search [conducted] was illegal in light of all
the circumstances.‖ Herring, 555 U.S. at 145 (internal
quotation marks omitted) (quoting Leon, 468 U.S. at 922
n.23). Davis is obviously important because the facts in that
case—officer reliance on ―binding appellate precedent‖—are
the most analogous of the Supreme Court‘s several good-faith
cases with which the Government, and we, have to work.
Regardless, the predominant importance of Davis is its




                               9
affirmation of deterrence and police culpability as the
lynchpins of the exclusionary rule analysis. The majority
thus erroneously elevates the ―binding appellate precedent‖
language to its own good-faith test instead of treating it as a
single consideration in the exclusionary rule analysis.

        Nevertheless, ―of great significance to the instant
case,‖ the majority insists, ―is the fact that in Davis the police
relied on binding appellate precedent that ‗specifically
authorize[d the] particular police practice.‘‖ Maj. Op. at 39
(quoting Davis, 131 S. Ct. at 2429). Thus, the majority
stresses, that Davis must be read as ―extend[ing] good faith
protection only to acts that are explicitly sanctioned by clear
and well-settled precedent.‖ Maj. Op. at 40. First, I take
great issue with the majority‘s suggestion that the good-faith
exception was ―extend[ed]‖ by Davis, or any other case,
―only‖ to the specific factual circumstances therein. Courts
apply a single good-faith exception to either condone or
condemn varying factual circumstances. See Davis, 131 S.
Ct. at 2428 (―The Court has over time applied [the] ‗good-
faith‘ exception across a range of cases.‖).

       More importantly, the Davis dissent, other courts, and
commentators do not read the Davis majority‘s articulation of
the good-faith exception as limited to only ―binding appellate
precedent.‖ See Davis, 131 S. Ct. at 2439 (Breyer, J.,
dissenting) (―[A]n officer who conducts a search that he
believes complies with the Constitution but which, it
ultimately turns out, falls just outside the Fourth
Amendment‘s bounds is no more culpable than an officer
who follows erroneous ‗binding precedent.‘ Nor is an officer
more culpable where circuit precedent is simply suggestive
rather than ‗binding,‘ where it only describes how to treat




                               10
roughly analogous instances, or where it just does not exist.‖);
United States v. Sparks, 

, 63 (1st Cir. 2013) (―The
[Davis] Court‘s emphasis on the absence of police culpability
could be read to imply that good-faith reliance on out-of-
circuit appellate precedent is also acceptable.‖); United States
v. Baez, 

, 294–95 (D. Mass. 2012) (―Baez
argues that Davis should be limited to its precise holding. . . .
[But] th[at] interpretation is entirely too static . . . . It is
apparent that both the majority opinion and the concurring
and dissenting opinions anticipated the principles of Davis
would be worked out in subsequent cases raising themes and
variations.‖); Orin S. Kerr, Fourth Amendment Remedies and
Development of the Law: A Comment on Camreta v. Greene
and Davis v. United States, 2011 CATO SUP. CT. REV. 237,
255 (2011) (―If the exclusionary rule solely concerns
culpability . . . its [sic] hard to see why binding precedent is
required. Reliance on binding precedent seems inherently
reasonable, but reliance is often reasonable without binding
precedent. A local police officer who conducts a search
widely upheld among the circuits but not yet addressed by the
[U.S. Court of Appeals] in his jurisdiction is no more
culpable than an officer who conducts a search upheld only
by his regional circuit. If the former has acted reasonably,
then surely so has the latter.‖).2

       2
         The majority supports its limiting reading of Davis
by pointing to the opinion below from the Eleventh Circuit,
and several similar cases from our sister circuits, wherein
courts ―stress. . . that [the] precedent on a given point must be
unequivocal before [those courts would] suspend the
exclusionary rule‘s operation.‖ United States v. Davis, 

, 1266 (11th Cir. 2010); see also United States v.
McCane, 

, 1045 (10th Cir. 2009) (―Relying




                               11
       Finally, the majority argues that Davis itself forecloses
the conclusion that law enforcement reliance on analogous or
non-binding out-of-circuit precedent could ever constitute
good faith. Quoting language from Davis,3 the majority


upon the settled case law of a United States Court of Appeals
certainly qualifies as an objectively reasonable law
enforcement behavior.‖); United States v. Jackson, 

, 866 (5th Cir. 1987) (―The exclusionary rule should not
be applied to searches which relied on Fifth Circuit law prior
to the change of that law . . . .‖); id. at 878 (Hill, J.,
concurring) (―Outside of situations where we have authorized
the specific conduct undertaken and then later declared it
unconstitutional, I believe the analogy to Leon and Krull
weakens and the exception should probably not be applied.‖).
But the Supreme Court refrained from creating a similar
restraint. See Davis, 131 S. Ct. at 2435–36 (Sotomayor, J.,
concurring) (noting that Davis left ―the markedly different
question [of] whether the exclusionary rule applies when the
law governing the constitutionality of a particular search is
unsettled . . . unanswered‖). I therefore hesitate before
reading into Davis a limitation apparently at odds with its
rationale. See Kerr, supra at 255.
       3
           The language quoted by the majority reads as
follows:
      This Court reviews criminal convictions from
      12 Federal Courts of Appeals, 50 state courts of
      last resort, and the District of Columbia Court
      of Appeals. If one or even many of these courts
      uphold a particular type of search or seizure,
      defendants in jurisdictions in which the
      question remains open will still have an




                              12
claims that the case explained that ―its holding was limited to
jurisdiction[s] where the law was clearly settled.‖ Maj. Op. at
42 n.17. But the language to which the majority refers,
quoted in full at footnote 3, supra, is pure dicta, responding
not to an argument about what the good-faith exception
should or should not apply to but to the policy concern that
―applying the good-faith exception to searches conducted in
reliance on binding precedent will stunt the development of
Fourth Amendment law.‖ Davis, 131 S. Ct. at 2432; see also
id. at 2433 (―[A]pplying the good-faith exception in this
context will not prevent judicial reconsideration of prior
Fourth Amendment precedents.‖).4 Furthermore, directly



       undiminished incentive to litigate the issue.
       This Court can then grant certiorari, and the
       development of Fourth Amendment law will in
       no way be stunted.
Davis, 131 S. Ct. at 2433.
      4
          As an aside, I fail to see how allowing law
enforcement reliance on analogous or non-binding out-of-
circuit precedent to influence substantially the good-faith
analysis would foreclose development of Fourth Amendment
law. Leon made clear that ―[t]here is no need for courts to
adopt the inflexible practice of always deciding whether the
officers‘ conduct manifested objective good faith before
turning to the question [of] whether the Fourth Amendment
has been violated.‖ 468 U.S. at 924. ―Defendants seeking
suppression of the fruits of allegedly unconstitutional
searches or seizures undoubtedly raise live controversies‖
which federal courts are ―empower[ed] . . . to adjudicate‖;
and ―courts have considerable discretion in conforming their




                              13
preceding this brief discussion, the Court reiterated that the
sole focus of the exclusionary rule is ―deterrence of culpable
law-enforcement conduct.‖ Id. at 2432–33.

        In short, I disagree with the way the majority‘s opinion
reads to suggest that Davis alone answers the questions
presented in this appeal. In Davis, the Court was presented
with a unique set of facts to which its holding was expressly
directed: officer reliance on ―binding appellate precedent‖
later overruled. See Davis, 131 S. Ct. at 2429. Identified by
both the concurrence and the dissent, Davis did not touch the
questions of ―whether the exclusionary rule applies when the
law governing the constitutionality of a particular search is
unsettled,‖ id. at 2435 (Sotomayor, J., concurring), or ―where
circuit precedent is simply suggestive rather than ‗binding,‘
where it only describes how to treat roughly analogous
instances, or where it just does not exist,‖ id. at 2439 (Breyer,
J., dissenting).

       Of paramount importance to this case is that the
reasoning underlying Davis does address those questions.
Davis and the Court‘s good-faith jurisprudence teach us that
we must look at the totality of the circumstances and ask
whether, in light of those circumstances, the officers were
acting with ―deliberate, reckless, or grossly negligent
disregard for Fourth Amendment rights,‖ which would justify
suppression, or, instead, whether they were acting ―with an
objectively reasonable good-faith belief that their conduct
[was] lawful‖ or ―involve[d] only simple, isolated
negligence.‖ Davis, 131 S. Ct. at 2427–28 (citations and


decisionmaking processes to the exigencies of particular
cases.‖ Id. at 924–25.




                               14
internal quotation marks omitted). For that reason, I disagree
with the majority‘s conclusion that authority falling outside
the specific semblance of Davis is ―different‖ and thus always
insufficient to support a finding of good-faith in every
circumstance.

       In Davis, the Court explained that Leon ―imported‖ the
reasoning of United States v. Peltier, 

 (1975)
―into the good-faith inquiry.‖ Davis, 131 S. Ct. at 2432. In
Peltier, border patrol agents conducted a stop-and-search of
an automobile ―within a reasonable distance from‖ the
Mexican border pursuant to a federal statute, federal
regulations promulgated in accordance with that statute, and a
―continuous judicial approval‖ of ―the statute and the . . .
policy‖ across the federal courts. Peltier, 422 U.S. at 540–42.
Although that statute and policy were overturned by the
Court‘s decision in Almeida-Sanchez v. United States, 

 (1973), the Peltier Court refrained from applying
the exclusionary rule. See id. at 542.

       Essential to the Peltier Court‘s decision was the now-
familiar reasoning that ―evidence obtained from a search
should be suppressed only if it can be said that the law
enforcement officer had knowledge, or may properly be
charged with knowledge, that the search was unconstitutional
under the Fourth Amendment.‖ Id. Especially relevant here,
the Court stated that ―unless we are to hold that parties may
not reasonably rely upon any legal pronouncement emanating
from sources other than this Court, we cannot regard as
blameworthy those parties who conform their conduct to the
prevailing statutory or constitutional norm.‖ Id.




                              15
       Thus, if the logic of Peltier was ―imported . . . into the
good-faith inquiry‖ as Davis states, 131 S. Ct. at 2432, then a
―uniform treatment‖ of a particular law enforcement act by
the federal judiciary or a ―prevailing . . . norm‖ can, in the
proper circumstances, support a finding of good faith. See
Herring, 555 U.S. at 145 (―‗[O]ur good-faith inquiry is
confined to the objectively ascertainable question whether a
reasonably well trained officer would have known that the
search was illegal‘ in light of ‗all the circumstances.‘‖
(quoting Leon, 468 U.S. at 922 n.23)); cf. United States v.
Duka, 

, 347 n.12 (3d Cir. 2011) (noting that
―[t]he objective reasonableness of the officers‘ reliance on the
statute . . . is further bolstered by the fact that the particular
provision at issue had been reviewed and declared
constitutional by several [out-of-circuit] courts‖ (citing Davis,
131 S. Ct. at 2434)).

       All in all, my problem with the method of the
majority‘s good-faith analysis is that it myopically focuses
too much on the facts and narrow holdings of Davis and other
good-faith cases, and considers too little, if at all, the
reasoning and principles of law underlying those decisions.
The majority‘s analysis is a search for some sort of
―immutable authority or information that justifies [the law
enforcement officers‘] course of action.‖ See Maj. Op. at 36.
But the good-faith exception to the exclusionary rule is not
limited to those circumstances. The good-faith inquiry, like
other Fourth Amendment analyses, requires us to ―slosh our
way through the factbound morass of ‗reasonableness.‘‖
Scott v. Harris, 

, 383 (2007).5 The question is,

       5
         The majority insinuates that my analysis would
―burden district courts with [an unwarranted] type of case-by-




                               16
and always has been, whether the officers acted with a
―reasonable good-faith belief that a search or seizure was in
accord with the Fourth Amendment.‖ Leon, 468 U.S. at 909
(quoting Gates, 462 U.S. at 255 (White, J., concurring)); see
also Davis, 131 S. Ct. at 2427–28; Herring, 555 U.S. at 145;
Evans, 514 U.S. at 11–12; Krull, 480 U.S. at 348–49. Davis
answers ―yes‖ to police actions taken in reliance on ―binding
appellate precedent.‖ Davis, 131 S. Ct. at 2429. See also
Herring, 555 U.S. at 147–48 (answering ―yes‖ where officers
relied on an error in a police-maintained outstanding warrant
database); Evans, 514 U.S. at 14–16 (answering ―yes‖ where
officers relied on an error in court-maintained database);
Krull, 480 U.S. at 349–50 (answering ―yes‖ where officers
relied on a subsequently invalidated statute); Leon, 468 U.S.
at 922 (answering ―yes‖ where officers relied on a
subsequently invalidated warrant). What we are asked to
answer is whether the result is the same when officers act in



case assessment,‖ and create ―a sprawling, amorphous, and
self-contradicting doctrine.‖ Maj. Op. at 45. But all of the
questions that the majority fears—i.e., ―how many circuits
had addressed the police practice in question, what each one
said, whether the statements were mere dicta‖; and ―what if
our sister courts had all ruled in near-unanimity on a point,
with one stalwart (perhaps, highly persuasive) holdout?‖—
are exactly the sorts of questions we should be asking;
particularly where the Supreme Court instructs us to answer
the good-faith question by focusing on whether ―a reasonably
well trained officer would have known that the search
[conducted] was illegal in light of all the circumstances.‖
Herring, 555 U.S. at 145 (internal quotation marks omitted)
(quoting Leon, 468 U.S. at 922 n.23).




                             17
the circumstances in which they did here. As the following
analysis shows, I answer that question in the affirmative.

                             III.

                              A.

       Before determining if the officers in this case acted
with an objectively reasonable belief that their conduct
complied with the Fourth Amendment, we must first
determine what, precisely, their conduct was. Jones lumps
the police conduct that occurred here into a singular act, see
Jones, 132 S. Ct. at 949 (installation of a GPS and its use to
monitor a vehicle are a search), as does the majority. But
before Jones, GPS or GPS-like surveillance was often treated
as two distinct acts: (1) the installation of the GPS or GPS-
like device, and (2) the subsequent surveillance of the
automobile.6 Thus, for the purpose of my exclusionary rule
analysis, I find it appropriate to similarly separate the
officers‘ conduct here into those two distinct Fourth
Amendment acts. See Sparks, 711 F.3d at 66–67 (bifurcating

      6
         See, e.g., Karo, 468 U.S. at 711–13 (analyzing Fourth
Amendment implications of beeper installation); id. at 713–
18 (analyzing Fourth Amendment implications of beeper
surveillance); Knotts, 460 U.S. at 280 n.** (certiorari granted
on Fourth Amendment implications of beeper use and
―pass[ing]‖ on the issue of beeper installation); United States
v. Pineda-Moreno, 

, 1215–16 (9th Cir. 2010)
(analyzing GPS installation separately from GPS use); United
States v. Moore, 

, 111–12 (1st Cir. 1977) (same,
but with beepers).




                              18
its exclusionary rule / good-faith exception analysis with
regard to, first, the GPS‘s installation and, second, its
subsequent monitoring).7

                              B.

      Application of the exclusionary rule depends on
whether the officers, at the time they were acting, would have
or should have known their installation of the GPS and their

       7
         I pause to note that separating GPS use into these two
distinct Fourth Amendment acts is not appropriate for
determining whether a Fourth Amendment search has
occurred.      The Jones majority clearly rejected the
concurrence‘s suggestion that it do so. Compare Jones, 132
S. Ct. at 951 n.5 (finding the distinction between GPS
―installation‖ and ―use‖ irrelevant for determining whether a
Fourth Amendment ―search‖ had occurred, reasoning ―[a]
trespass on ‗houses‘ or ‗effects,‘ or a Katz invasion of
privacy, is not alone a search unless it is done to obtain
information; and the obtaining of information is not alone a
search unless it is achieved by such a trespass or invasion of
privacy‖), with id. at 958 (Alito, J., concurring) (finding it a
―questionable proposition that [the] two procedures cannot be
separated for purposes of the Fourth Amendment analysis,‖
and reasoning that it is clear that both the ―installation‖ and
―use‖ of the GPS, on their own, do not constitute a search).
But it is conceded that a search did occur in this case. My
analysis focuses on an entirely different question; to wit:
whether the officers would have known, at the time of their
actions, that their conduct was a ―search.‖ Because, as
discussed in supra note 6, this question was often bifurcated
at the time, my analysis proceeds accordingly.




                              19
subsequent use of the GPS to track Harry Katzin‘s vehicle
were unconstitutional. See Krull, 480 U.S. at 348–49.
Relevant to this determination are the Supreme Court‘s case
law dealing with electronic surveillance and general searches
of automobiles, subsequent treatment of GPS and GPS-like
surveillance across the federal courts, and other
considerations.

                              1.

        United States v. Knotts, 

 (1983) and
United States v. Karo, 

 (1984) are the authorities
most relevant to our analysis. In Knotts, Minnesota law
enforcement officers utilized an electronic beeper to conduct
surveillance on a vehicle driven by a man suspected to be part
of an illegal narcotics operation. 468 U.S. at 277–80. In
determining the Fourth Amendment implications of that
activity, the Court determined that the alleged search
―amounted principally to the following of an automobile on
public streets and highways.‖ Id. at 281. The Court rejected
the argument that this constituted a search under the Fourth
Amendment, and held that ―[a] person traveling in an
automobile on public thoroughfares has no reasonable
expectation of privacy in his movements from one place to
another.‖8 Id. Because when one drives an automobile on

      8
         At the time, this holding was in accord many of the
courts of appeals to have addressed the issue. A compelling
number of courts found beeper surveillance did not implicate
the Fourth Amendment. See, e.g., United States v. Michael,

, 257–58 (5th Cir. 1981) (en banc) (holding
―subsequent monitoring,‖ after installation of beeper upon
reasonable suspicion, ―did not violate . . . reasonable




                             20
expectation[s] of privacy‖); United States v. Hufford, 

, 33–34 (9th Cir. 1976) (holding one‘s movements in
his vehicle on a public road ―were knowingly exposed to the
public, and therefore are not a subject of Fourth Amendment
protection‖), partially overruled by Jones, 

, as
recognized by United States v. Pineda-Moreno, 

, 1091 (9th Cir. 2012); cf. United States v. Bruneau, 

, 1196–97 (8th Cir. 1979) (holding that ―monitoring
the airborne location of an aircraft with a [beeper] is not a
search within the fourth amendment‖); United States v.
Clayborne, 

, 350–51 (10th Cir. 1978) (holding
use of beeper ―as a substitute for persistent extensive visual‖
surveillance, when it enters a ―clandestine laboratory‖
exposed to ―outside viewing‖ and ―ingress and egress of the
public‖ did not per se violate the Fourth Amendment).

       Alternatively, some courts alluded that it implicated a
person‘s privacy interests, but did not hold such surveillance
required a warrant. See, e.g., United States v. Moore, 

, 111–12 (1st Cir. 1977) (holding beeper surveillance
requires probable cause, but no warrant), abrogated by United
States v. Knotts, 

, 286 (1983), as recognized by
United States v. Sparks, 

, 65 (1st Cir. 2013)
(―Knotts . . . abrogated Moore‘s probable cause requirement
for beeper surveillance . . . .‖); cf. United States v. Shovea,

, 1387–88 (10th Cir. 1978) (―The utilization of
an electronic tracking device, without prior court approval,
may be justified by probable cause and exigent
circumstances.‖). Conversely, a few cases did require a
formal warrant; but many of those cases involved installations
and surveillance occurring in private areas. See, e.g., United




                              21
public roads, he ―voluntarily convey[s] to anyone who
want[s] to look‖9 his location, progress, and route, he has no



States v. Bailey, 

, 944, 945–46 (6th Cir. 1980).
That was not the case in Knotts, nor is it the case here.

       The Fifth Circuit at one time held that beeper
surveillance plainly implicated the Fourth Amendment. See
United States v. Holmes, 

, 865–67 (5th Cir.
1975) (―A person has a right to expect that when he drives his
car into the street, the police will not attach an electronic
surveillance device to his car in order to track him. Although
he can anticipate visual surveillance, he can reasonably
expect to be ‗alone‘ in his car when he enters it and drives
away. . . . The[] failure to obtain a warrant is fatal.‖). But that
view seems to have been abrogated, if not overruled, by later
pre-Knotts cases. See Michael, supra.
       9
           The proposition that one has no reasonable
expectation of privacy in information willingly conveyed to
third parties remains unquestioned. Smith v. Maryland, 

, 743–44 (1979) (―This Court consistently has held
that a person has no legitimate expectation of privacy in
information he voluntarily turns over to third parties.‖); see
also, e.g., California v. Greenwood, 

, 40–41
(1988) (no reasonable expectation of privacy in garbage bags
willingly left on street curb for pick up by third party). But
see Jones, 132 S. Ct. at 957 (Sotomayor, J., concurring) (―[I]t
may be necessary to reconsider the premise that an individual
has no reasonable expectation of privacy in information
voluntarily disclosed to third parties.‖).




                                22
reasonable privacy interest in ―whatever stops he ma[kes]‖
nor his ―final destination‖ or otherwise. Id. at 281–82.10

       10
           The Knotts Court also based its holding on the
similarly well-established ―open fields‖ doctrine, see Air
Pollution Variance Bd. of Colo. v. W. Alfalfa Corp., 

, 864–65 (1974); United States v. Lee, 

, 563
(1927); Hester v. United States, 

, 59 (1924),
stating the beeper‘s ability to enhance visual surveillance was
of no consequence. Knotts, 460 U.S. at 282 (―Nothing in the
Fourth Amendment prohibited the police from augmenting
the sensory faculties bestowed upon them at birth with such
enhancement as science and technology afforded them in this
case.‖); see also Boyd v. United States, 

, 628
(1886) (―‗The eye cannot . . . be guilty of a trespass . . . .‘‖
(quoting Entick v. Carrington, 95 Eng. Rep. 807 (K.B.
1765))).     Technological enhancements of purely visual
surveillance have, since Knotts, received similar treatment.
See Florida v. Riley, 

, 488–52 (1989) (aerial
surveillance of interior of partially covered greenhouse from a
helicopter 400 feet overhead is not a search); Dow Chem. Co.
v. United States, 

, 238–39 (1986) (aerial
photographs taken from an airplane over an industrial
complex are not searches); California v. Ciraolo, 

, 211–14 (1986) (aerial surveillance of an open
greenhouse from an airplane 1,000 feet overhead is not a
search); Texas v. Brown, 

, 739–40 (1983)
(plurality opinion) (using flashlight to look into car interior
and open glove compartment at night is not a search). But see
Kyllo v. United States, 

, 33–34 (2001) (use of
infrared light technology to detect heat waves radiating off a
home is a search because that information ―could not
otherwise have been obtained without physical intrusion into




                              23
       A little over a year later, the Court reaffirmed this
conclusion in Karo. But Karo clarified that the use of
beepers to monitor cars and other objects was not without
limits. Only in situations in which officers employ electronic
devices to obtain information that could otherwise be
obtained by visual surveillance in public places are officers
able to rely upon Knotts‘s holding. See Karo, 468 U.S. at
713–16. Thus, the use of a beeper to monitor objects within
private residences implicates the Fourth Amendment and
requires a warrant. See id. at 714, 717–18.

       What Knotts initially left undecided, however, was
whether the installation of the beeper was a search under the
Fourth Amendment. See Knotts, 460 U.S. at 290 n.**; id. at
286 (Brennan, J., concurring). In both Knotts and Karo, the
officers themselves neither installed nor placed the beepers
onto or into the vehicles. In Knotts, the officers, with the
consent of a chemical manufacturing company, installed a
beeper inside a container for chemicals. The company agreed
that the next time a suspected narcotics manufacturer came to
purchase chemicals, they would put the chemicals he
purchased in that particular container. After purchasing the
chemicals, the suspect willingly placed the bugged container
into his car, allowing the police to easily monitor his
movements. 460 U.S. at 278. In Karo, the officers
cooperated with a government informant so as to ensure that
Karo, who was suspected of manufacturing narcotics, was
similarly duped into purchasing a container of chemicals


a constitutionally protected area‖ and ―the technology in
question [was] not in general public use‖ (internal quotation
marks omitted) (quoting Silverman v. United States, 

, 512 (1960))).




                             24
containing a beeper. Once the purchase had occurred, and
Karo placed the container in his car, the officers utilized the
beeper to monitor his movements. 468 U.S. at 708.

       Karo held that where officers arrange for a suspect to
obtain an item containing a beeper, even if the suspect has no
knowledge of the item‘s foreign tenant, that transfer did not
intrude upon that suspect‘s reasonable expectations of
privacy. Id. at 712. In short, the transfer ―created a potential
for an invasion of privacy,‖ but the mere fact that officers
arranged for a beeper to come into the possession of an
individual or into an individual‘s property ―infringed no
privacy interest.‖ Id. Moreover, Karo reasoned that ―[a]t
most, there was a technical trespass on the space occupied by
the beeper.‖ Id. But the Court concluded that ―[t]he
existence of a physical trespass is only marginally relevant to
the question of whether the Fourth Amendment has been
violated . . . , for an actual trespass is neither necessary nor
sufficient to establish a constitutional violation.‖ Id. at 712–
13.11 As a result, the Court held that ―any impairment of . . .

       11
          Karo‘s conclusion that ―an actual trespass is neither
necessary nor sufficient to establish a constitutional violation‖
was, until Jones, sacrosanct in Fourth Amendment law. In
Katz v. United States, 

 (1967), the Supreme
Court turned Fourth Amendment questions away from their
common-law trespass foundation. See 389 U.S. at 353
(―[T]he trespass doctrine . . . can no longer be regarded as
controlling.‖). Thereafter, the Fourth Amendment touchstone
was whether the government had intruded upon a person‘s
reasonable expectations of privacy. See id. at 360 (Harlan, J.,
concurring); see also Jones, 132 S. Ct. at 950; United States
v. Mosley, 

, 253 (3d Cir. 2006) (―[T]he Fourth




                               25
Amendment‘s protection against unreasonable searches is
predicated on the invasion by the government of a person‘s
reasonable expectation of privacy . . . .‖). For instance, in
Oliver v. United States, 

 (1984), the police
officers undoubtedly trespassed upon the petitioner‘s
property. But, because it was found that the officers were
trespassing upon only the ―open fields‖ of petitioner‘s
property, he could not ―demand privacy‖ for activities
conducted or incriminating evidence found upon that
property. 466 U.S. at 177–78. The vast consensus was, then,
that a physical ―trespass‖—regardless of whether it would
have been considered an actual ―trespass‖ under the common
law—became a ―search‖ only when that trespass infringed
upon a person‘s reasonable expectation of privacy. See, e.g.,
Rakas v. Illinois, 

, 143 (1978) (―[C]apacity to
claim the protection of the Fourth Amendment depends not
upon a property right in the invaded place but upon whether
the person who claims the protection of the Amendment has a
legitimate expectation of privacy in the invaded place.‖);
United States v. Acosta, 

, 1256–57 (3d Cir.
1992). Indeed, the courts of appeals addressing the Fourth
Amendment implications of GPS and GPS-like installation
after Knotts and Karo made little of the physical trespass that
occurred when police installed devices directly upon
automobiles, primarily because the invasion of privacy that
occurred was minimal or non-existent. See United States v.
Marquez, 

, 609–10 (8th Cir. 2010); United
States v. Pineda-Moreno, 

, 1215 (9th Cir.
2010); United States v. Garcia, 

, 997 (7th Cir.
2007); United States v. McIver, 

, 1126–27 (9th
Cir. 1999); see also United States v. Michael, 

,
257–58 (5th Cir. 1981).




                              26
privacy interests that may have occurred was occasioned by
the monitoring of the beeper,‖ not its installation. Id. at
713.12

        Thus, at bottom, before Jones, Knotts and Karo
established that no Fourth Amendment search occurred where
officers use beeper-based electronics to monitor an
automobile‘s movements on public roads because a person
has no reasonable expectation of privacy with regard to that
information. But, because the facts of Karo correspondingly
limited its holding, those cases did not address whether
installation of a beeper onto or into a vehicle, in all
circumstances, was a search. Nonetheless, Karo‘s reasoning
regarding the Fourth Amendment implications of a beeper
installation on an automobile is telling, and was certainly
informative in the subsequent treatment of the issue
throughout the federal courts.

     Additionally, several other well settled Fourth
Amendment principles are relevant. Before Jones, the


      12
          The Karo Court also rejected the argument that the
transfer of the bugged container constituted a seizure, holding
that no ―possessory interest was interfered with in a
meaningful way.‖ Karo, 468 U.S. at 712; see also id. (―A
‗seizure‘ of property occurs when ‗there is some meaningful
interference with an individual‘s possessory interests in that
property.‘‖ (quoting United States v. Jacobsen, 

,
113 (1984)). Later cases did not disturb this holding, see,
e.g., United States v. Garcia, 

, 996 (7th Cir.
2007), and Appellees here do not allege the GPS installation
or subsequent surveillance was a seizure.




                              27
Supreme Court had made perfectly clear that persons did not
enjoy a reasonable expectation of privacy in the exterior of
their automobiles. New York v. Class, 

, 114
(1986); see also Cardwell v. Lewis, 

, 591 (1974).
Similarly axiomatic were the principles that a simple
―trespass‖ or ―physical intrusion‖ alone, absent an
infringement upon a reasonable expectation of privacy, was
not a ―search,‖ see supra Note 11; that information willingly
conveyed to third parties, such as when a car ―travels public
thoroughfares where its occupants and its contents are in plain
view,‖ Cardwell, 417 U.S. at 590, retains no reasonable
expectation of privacy, see supra Note 9; and that objects
willingly placed or left in the ―open fields,‖ regardless of
whether those fields are trespassed upon, see Oliver, 466 U.S.
at 177–80, do not enjoy a reasonable expectation of privacy,
see supra Note 10.

                              2.

        After Knotts and Karo, what resulted was a uniform
consensus across the federal courts of appeals to address the
issue that the installation and subsequent use of GPS or GPS-
like device was not a search or, at most, was a search but did
not require a warrant. See, e.g., United States v. Marquez,

, 609–10 (8th Cir. 2010) (reasoning that
installation and use of GPS requires only reasonable
suspicion, since monitoring on public roads is not a search);
United States v. Pineda-Moreno, 

, 1215–16
(9th Cir. 2010) (holding that GPS installation and use was not
a search); United States v. Garcia, 

, 997–98 (7th
Cir. 2007) (same); United States v. McIver, 

,
1126–27 (9th Cir. 1999) (same); see also United States v.
Michael, 

, 256–58 (5th Cir. 1981) (en banc)




                              28
(holding that installation and use of beeper requires only
reasonable suspicion, since monitoring on public roads is not
a search).13

       Most federal district courts, including the Middle
District of Pennsylvania, had reached the same result. United
States v. Jesus-Nunez, No. 1:10-cr-00017-01, 

, **3–5 (M.D. Pa. July 27, 2010) (―Since there was
no Fourth Amendment search or seizure by the Government‘s
use of the GPS device, the court finds that the agents did not
need probable cause or even reasonable suspicion to attach
and monitor the [GPS] device to Defendant‘s cars.‖); e.g.,
United States v. Burton, 

, 1307–08
(N.D. Fla. 2010); United States v. Moran, 

, 467–68 (N.D.N.Y. 2005).

       The only case to break from this consensus was United
States v. Maynard, 

 (D.C. Cir. 2010). In
Maynard, the D.C. Circuit held that prolonged use of a GPS
device to monitor the movements of defendant Jones‘s
vehicle ―24 hours a day for four weeks,‖ was a ―search‖
under the Fourth Amendment. 615 F.3d at 555. According to
the D.C. Circuit, Knotts was not controlling of the question,
as the court reasoned that Knotts‘s holding endorsed only that

      13
           Michael was also the law in the Eleventh Circuit.
See Bonner v. City of Prichard, 

, 1209 (11th
Cir. 1981) (en banc) (decisions of the Fifth Circuit prior to
October 1, 1981 are binding on the Eleventh Circuit); United
States v. Smith, 387 F. App‘x 918, 920–21 (11th Cir. 2010)
(unpublished) (citing United States v. Michael, 

(5th Cir. 1981) to support the proposition that GPS
installation was not a search).




                             29
―‗[a] person traveling in an automobile on public
thoroughfares has no reasonable expectation of privacy in his
movements from one place to another,‘ not that such a person
has no reasonable expectation of privacy in his movements
whatsoever, world without end.‖ Id. at 557 (alteration in
original) (citation omitted) (quoting Knotts, 460 U.S. at 281).
The court reasoned that the Supreme Court in Knotts, and the
later cases across the courts of appeals, all ―reserved‖ the
issue of ―whether ‗wholesale‘ or ‗mass‘ electronic
surveillance of many individuals requires a warrant.‖ Id. at
558.14

        As a result, the court concluded that although it may be
―one thing for a passerby to observe or even to follow
someone during a single journey as he goes to the market or
returns home from work,‖ it is a whole other thing ―for that
stranger to pick up the scent again the next day and the day
after that, week in and week out, dogging his prey until he has
identified all the places, people, amusements, and chores that
make up that person‘s hitherto private routine.‖ Id. at 560.
The court‘s analysis in Maynard, therefore, was focused not
on the installation of the device but rather the prolonged use

       14
          The Supreme Court in Knotts, in response to the
argument that its holding would allow ―twenty-four hour
surveillance of any citizen of this country . . . without judicial
knowledge or supervision,‖ opined that ―the ‗reality hardly
suggests abuse,‘‖ and suggested that ―if such dragnet-type
law enforcement practices . . . should eventually occur, there
will be time enough then to determine whether different
constitutional principles may be applicable.‖ Knotts, 460
U.S. at 283–84 (quoting Zurcher v. Stanford Daily, 

, 566 (1978)).




                               30
of the GPS and the quality and quantity of information
obtained over an extended period of time. Id. at 562
(―Prolonged surveillance reveals types of information not
revealed by short-term surveillance, such as what a person
does repeatedly, what he does not do, and what he does
ensemble. These types of information can each reveal more
about a person than does any individual trip viewed in
isolation.‖).15

       Other than Maynard, only a handful of dissenting
opinions questioned Knotts‘s and Karo‘s holdings or their
applicability to GPS installation and subsequent surveillance.
See Karo, 468 U.S. at 736 (Stevens, J., dissenting) (―The
impact of beeper surveillance upon interests protected by the
Fourth Amendment leads me to what I regard as the perfectly
sensible conclusion that absent exigent circumstances
Government agents have a constitutional duty to obtain a
warrant before they install an electronic device on a private
citizen‘s property.‖); United States v. Pineda-Moreno, 

, 1124–26 (9th Cir. 2010) (Kozinski, C.J.,
dissenting from denial of rehearing en banc) (arguing that

      15
          I pause here to note that the majority characterizes
Maynard as having held that the mere act of attaching a GPS
device onto a person‘s vehicle for the purpose of conducting
continual surveillance, alone, constituted a search. See Maj.
Op. at 16; see also id. at 27 n.9 (describing that Maynard
―explained that warrantless installation of a GPS device by
the police was per se unreasonable under the Fourth
Amendment‖). Such a characterization is unfaithful to the
panel‘s opinion, which explicitly tailored its holdings to the
fact that the surveillance conducted in that case lasted for a
month. See Maynard, 615 F.3d at 558, 560.




                             31
GPS surveillance is a search because GPS devices ―have little
in common with the primitive devices in Knotts,‖ and provide
officers ―the power to track the movements of every one of
us, every day of our lives‖); Michael, 645 F.2d at 260–70
(Tate, J., dissenting) (disagreeing with majority that ―an
individual living under our Constitution has no reasonable
expectation of privacy such as would protect him from a
trespass upon his property by governmental agents, a trespass
that enables them to maintain continuous electronic
surveillance over his movements twenty-four hours per day
continuously and indefinitely‖).

                               3.

        I also find several other considerations relevant. First,
and most important, is Rule 41(b) of the Federal Rules of
Criminal Procedure, which governs the issuance of warrants
in all federal criminal proceedings. The 2006 Advisory
Committee‘s Note explains that Rule 41(b) was amended, in
part, to ―address the use of tracking devices.‖ Fed. R. Crim.
P. 41(b) advisory comm. note (2006). In describing the ideal
procedure, the Note states that ―[w]arrants may be required to
monitor tracking devices when they are used to monitor
persons or property in areas where there is a reasonable
expectation of privacy.‖ Id. (citing Karo, 

).
Elaborating, the note instructs that ―if the officers intend to
install or use the device in a constitutionally protected area,
they must obtain judicial approval to do so.‖ Id. But, ―[i]f,
on the other hand, the officers intend to install and use the
device without implicating any Fourth Amendment rights,
there is no need to obtain the warrant.‖ Id. (citing Knotts,

).




                               32
        Moreover, the law enforcement officers consulted with
an Assistant United States Attorney before conducting the
installation of the GPS unit and the subsequent surveillance.
(See Appellant Br. at 56.) I agree with the majority that ―a
government attorney‘s approval, standing alone, cannot and
should not suffice to demonstrate good faith.‖ Maj. Op. at 52
n.23. But, as Appellees‘ attorney conceded at oral argument,
it is certainly another consideration to take into account in the
good-faith analysis. (See Oral Arg. Trans. at 52: 4–6
(conceding that the officers‘ reliance on the opinion of an
Assistant United States Attorney was ―a factor to look at‖ in
determining whether the officers acted in good faith).) See
also Tracey, 597 F.3d at 153 (concluding that approval from a
government attorney, inter alia, was one consideration
evidencing that ―[a] reasonable officer would . . . have
confidence in the validity of the [search]‖); United States v.
Otero, 

, 1134 (10th Cir. 2009) (same); United
States v. Fama, 

, 837 (2d Cir. 1985) (same).

                              IV.

      In my view, in light of the legal landscape discussed
above, when the officers installed the GPS device16 upon the
undercarriage of Harry Katzin‘s vehicle, and then used that

       16
          By ―installed the GPS device,‖ of course, I mean
that the officers magnetically attached the ―slap on‖ GPS
device upon the undercarriage of Harry Katzin‘s vehicle.
That device was totally independent of the car, operating
under its own power. Also, it was not physically installed
onto the car using screws, adhesives, or otherwise. Its
attachment was occasioned only magnetically. Thus, for the
purpose of my analysis, I focus on those facts.




                               33
device to monitor the vehicle‘s movements for two days
while it traversed public thoroughfares, those officers were
acting with ―an objectively ‗reasonable good-faith belief‘ that
their conduct [was] lawful.‖ Davis, 131 S. Ct. at 2427
(quoting Leon, 468 U.S. at 909). I find that the officers‘
actions in this case do not ―exhibit ‗deliberate,‘ ‗reckless,‘ or
‗grossly negligent‘ disregard for Fourth Amendment rights,‖
id. (quoting Herring, 555 U.S. at 144), and, thus, ―the
deterrent value‖ of excluding the evidence found pursuant to
the officers‘ conduct would not ―outweigh the resulting
costs.‖ Id. Simply put, in this case, ―exclusion cannot not
‗pay its way.‘‖ Id. at 2428 (quoting Leon, 468 U.S. at 908
n.6).

                               A.

       The officers here were acting with an objectively
reasonable good-faith belief that their warrantless installation
of the GPS device upon the undercarriage of Harry Katzin‘s
automobile did not run afoul of the Fourth Amendment.

       Based on fundamental Fourth Amendment principles
which would have been familiar to any reasonably well
trained law enforcement officer, there was no possibility that
the officers, at the time they installed the GPS upon Harry
Katzin‘s vehicle, would have ―had knowledge‖—nor could
we now ―charge[] [them] with knowledge‖—―that the search
was unconstitutional under the Fourth Amendment.‖ Krull,
480 U.S. at 348–49 (quoting Peltier, 422 U.S. at 542).

      Before Jones, the touchstone of any Fourth
Amendment analysis was whether the Government had
invaded upon a person‘s reasonable expectation of privacy.




                               34
See Katz, 389 U.S. at 360 (Harlan, J., concurring); see also
Bond v. United States, 

, 338 (2000); California
v. Ciraolo, 

, 211 (1986). ―[A]n actual trespass
[was] neither necessary nor sufficient to establish a
constitutional violation.‖ Karo, 468 U.S. at 713 (emphasis
added); see also supra note 11. As a result, a reasonably well
trained law enforcement officer would have known that the
installation of the GPS unit upon the undercarriage of Harry
Katzin‘s vehicle was a Fourth Amendment ―search‖ only in
the event that it was apparent that Harry Katzin had a
reasonable expectation of privacy in that area.

        Of course, Harry Katzin had a reasonable expectation
of privacy with respect to the interior of his vehicle; even if
that privacy interest was diminished. See Cardwell, 417 U.S.
at 589–90. But it would have been objectively reasonable for
a law enforcement officer to conclude that he lacked a
reasonable expectation of privacy in the exterior—
specifically, the undercarriage—of the vehicle.

       In Cardwell v. Lewis, 

 (1974) and again
in New York v. Class, 

 (1986), the Supreme
Court made it quite clear that persons lack a reasonable
expectation of privacy in the exterior of their automobiles.
See Cardwell, 417 U.S. at 591 –92 (―With the search limited
to the examination of the tire on the wheel and the taking of
paint scrapings from the exterior of the vehicle left in the
public parking lot, we fail to comprehend what expectation of
privacy was infringed.‖); Class, 475 U.S. at 114 (plurality
opinion) (―The exterior of a car, of course, is thrust into the
public eye, and thus to examine it does not constitute a
‗search.‘‖ (citing Cardwell, 417 U.S. at 588–89)). In light of
this long-standing Supreme Court precedent, the officers




                              35
would have had an ―objectively reasonable good-faith belief‖
that Harry Katzin lacked a reasonable expectation in the
exterior of his vehicle, and thus that ―their conduct was
lawful‖ when they installed the GPS on the car‘s
undercarriage. Davis, 131 S. Ct. at 2427 (internal quotation
mark omitted).17

       Again, I make no claim that Class or Cardwell qualify
as ―binding appellate precedent‖ under Davis. That does not
end the inquiry, however. Instead, what resolves the inquiry
is that, in light of the pre-Jones legal landscape, the law
enforcement officers here could have reasonably concluded
that Supreme Court precedent authorized, or at the very least
affirmed the constitutionality of, their conduct. Regardless of

       17
           The majority is correct to point out, in its brief
discussion of Class‘s applicability to our warrant analysis,
that Jones dismissed Class‘s relevancy with regard to whether
a search occurs where officers install and subsequently track a
GPS device upon an automobile. See Maj. Op. at 34 n.14.
That does not mean, however, that Class and Cardwell are
similarly irrelevant to our good-faith analysis. At the time the
officers were acting, those two cases were generally
understood to stand for the proposition that one lacks a
reasonable expectation of privacy in the exterior of his
automobile. See, e.g., Pineda-Moreno, 591 F.3d at 1215
(―[T]he undercarriage of a vehicle, as part of its exterior, is
not entitled to a reasonable expectation of privacy.‖); United
States v. George, 

, 1119–20 (4th Cir. 1992)
(―There is thus little question in the aftermath of Cardwell
and Class that one does not have a reasonable expectation of
privacy in the visible exterior parts of an automobile that
travels the public roads and highways.‖).




                              36
the alternate facts in Class and Cardwell, those cases‘
holdings and principles of law, which would have been
known by a reasonably well trained law enforcement officer,
made it clear that before Jones a person lacked a reasonable
expectation of privacy in the exterior of his automobile, and,
thus, a simple trespass thereupon by law enforcement officers
would not have constituted a ―search.‖ As a result, I cannot
conclude that the law enforcement officers‘ conduct in
installing the GPS device to the undercarriage of Harry
Kaztin‘s vehicle was a ―‗deliberate,‘ ‗reckless,‘ or ‗grossly
negligent‘ disregard of Fourth Amendment rights.‖ Davis,
131 S. Ct. at 2427 (quoting Herring, 555 U.S. at 144).

                              B.

       Similarly, the officers here were acting with an
objectively reasonable good-faith belief that their warrantless
use of the GPS to monitor Harry Katzin‘s vehicle while it
traversed public roads over the course of two days was
constitutionally permissible.

        First, the majority distinguishes, and thus dismisses,
Knotts and Karo on their facts. Paramount, the majority says,
are that facts that ―[n]either case involved a physical trespass
onto the target vehicle; in both cases the police placed the
beeper inside of a container which was then loaded into the
target vehicle by the driver . . . . [and] both Karo and Knotts
addressed the use of beepers, which . . . are markedly
different from GPS trackers.‖ Maj. Op. at 40. True, these
factual distinctions would matter much if the Government
were arguing that Knotts and Karo qualified as ―binding
appellate precedent‖ under Davis. But, as discussed above,
that is not the Government‘s argument. A reasonably well




                              37
trained police officer, acting in December 2010, would have
thought Knotts and Karo to have meant exactly what they
said with regard to GPS and GPS-like surveillance. Those
cases made absolutely clear that ―[a] person traveling in an
automobile on public thoroughfares has no reasonable
expectation of privacy in his movements from one place to
another,‖ Knotts, 460 U.S. at 281, because the ―movements
of the automobile‖ while on public roads ―could have been
observed by the naked eye.‖ See Karo, 468 U.S. at 713–14.
Thus, the Fourth Amendment simply was not implicated. See
id.; see also Sparks, 711 F.3d at 65 (―After Knotts . . . [it was]
settled . . . [that] using a beeper to monitor a person‘s
movements in a car on public roads did not implicate the
Fourth Amendment, because there was no privacy interest to
be infringed.‖). At the time the officers were acting, Knotts‘s
holding was familiar and sacrosanct. See, e.g., Marquez, 605
F.3d at 609; Garcia, 474 F.3d at 996; McIver, 186 F.3d at
1126.

        This may well be enough to justify the officers‘ good
faith in performing warrantless GPS surveillance of Harry
Katzin‘s automobile. See Sparks, 711 F.3d at 66–67
(concluding good-faith exception applied to GPS surveillance
because Knotts ―clearly authorized the agents to use a GPS-
based tracking device‖). But I need not answer that question,
because ―good faith‖ is determined in light of ―all of the
circumstances.‖ Leon, 468 U.S. at 922 n.23; see also
Herring, 555 U.S. at 145. In this case, in addition to Knotts
and Karo, the officers were also guided, and reasonably
relied, upon a ―uniform treatment‖ of ―continuous judicial
approval‖ across the federal courts with regard to the
constitutionality of warrantless GPS use. See Peltier, 422
U.S. at 541–42; see also Caleb Mason, New Police




                               38
Surveillance Technologies and the Good-Faith Exception:
Warrantless GPS Tracker Evidence After United States v.
Jones, 13 NEV. L. J. 60, 65 (2012) (before Jones, ―everyone
thought‖ that the ―key fact‖ from Knotts and Karo ―was that
the cars were being monitored while they were on public
roads, where anyone could see them‖). Specifically, nearly
every federal court to consider the issue had concluded that a
warrant was unnecessary to conduct GPS surveillance, the
sole exception being Maynard.18

        Consequently, in light of Knotts and Karo, and their
subsequent treatment, it was ―objectively reasonable‖ for the
law enforcement officers to have believed that the use of the
GPS device to conduct surveillance upon Harry Katzin‘s
vehicle while it moved along public roadways was not a
Fourth Amendment ―search.‖ See Knotts, 460 U.S. at 282–83
(explaining that where one ―travel[s] over the public streets
he voluntarily convey[s] to anyone who want[s] to look the
fact that he [is] traveling over particular roads in a particular
direction, the fact of whatever stops he ma[kes], and the fact
of his final destination‖); Ciraolo, 476 U.S. at 224 (Powell, J.,
dissenting) (―Comings and goings on public streets are public
matters, and the Constitution does not disable police from
observing what every member of the public can see.‖); id. at
215 (majority opinion) (―The Fourth Amendment simply does


       18
          The majority claims that, under the logic of my
analysis, Maynard should have put the law enforcement
officers ―on notice that [GPS] devices could implicate Fourth
Amendment rights.‖ Maj. Op. at 54 n.24 (alteration,
omission, and internal quotation marks omitted). For the
reasons set forth at infra Part V, I disagree.




                               39
not require the police traveling in the public . . . to obtain a
warrant in order to observe what is visible to the naked eye.‖).

                            C.

      Moreover, two additional considerations bolster my
conclusion that the law enforcement officers here acted with
―an objectively ‗reasonable good-faith belief‘ that their
conduct was lawful.‖ Davis, 131 S. Ct. at 2427 (quoting Leon,
468 U.S. at 909).

        First is the fact that the warrantless installation of the
GPS device and its subsequent surveillance complied with the
commentary to Rule 41(b) of the Federal Rules of Criminal
Procedure, which states that ―[i]f . . . the officers intend to
install and use [a GPS] device without implicating any Fourth
Amendment rights, there is no need to obtain [a] warrant.‖
FED. R. CRIM. P. 41(b) advisory comm. note (2006). As
discussed, it was objectively reasonable for the officers to
have concluded that Harry Katzin lacked a reasonable
expectation of privacy in the undercarriage of his automobile,
and the GPS device was never used to conduct surveillance in
any area but the public roadways upon which the car was
traveling. Thus, a reasonable reading of this commentary
would have led to the equally reasonable conclusion that the
officers here did not require a warrant to act.19

       19
          Although the Government neglected to argue this
fact, similar arguments have been made in similar cases,
including cases heard by District Courts in this Circuit. See,
e.g., United States v. Lopez, __ F. Supp. 2d __, C.A. No. 10-
cr-67(GMS), 

, at *3 (D. Del. June 26,
2013); United States v. Willford, __ F. Supp. 2d __, Crim. No.




                                 40
        Second, the law enforcement officers consulted with
an Assistant United States Attorney before conducting the
installation of the GPS unit and the subsequent surveillance.
(See Appellant Br. at 56.) More than likely, that attorney‘s
discussion with the officers about the constitutionality of their
conduct proceeded along similar lines as my analysis above.
But, important for our purposes, the fact that the officers
consulted with a government attorney before acting, who then
approved their desired course of action, although certainly not
dispositive on its own, is a consideration weighing in favor of
the conclusion that ―[a] reasonable officer would . . . have
confidence in the validity of the [search].‖ Tracey, 597 F.3d
at 153; see also Otero, 563 F.3d at 1134; Fama, 758 F.2d at
837.

       Thus, taking into consideration the Supreme Court
jurisprudence, the near unanimous treatment by the federal


ELH-11-0258, 

, at *20 (D. Md. June 7,
2013). Furthermore, the majority claims this commentary is a
codification of ―nothing more than the unremarkable
proposition that the police need not obtain a warrant if their
action does not violate the Fourth Amendment.‖ Since
Maynard put law enforcement ―on notice‖ that GPS use could
affect Fourth Amendment rights, the majority reasons, the
Rule has no substantive effect on the good-faith analysis.
Maj. Op. at 54 n.24. Again, as I discuss at infra Part V, I do
not read Maynard to have such an effect, and, thus, I am at a
loss to see how a reasonably well trained law enforcement
officer, acting at the time the officers did in this case, could
have known that their actions ―implicat[ed] . . . the Fourth
Amendment.‖




                               41
courts to have addressed the issue, the commentary to Rule
41(b) of the Federal Rules of Criminal Procedure, and the fact
the officers here consulted with an Assistant United States
Attorney, it is clear that the officers were not acting with
―‗deliberate,‘ ‗reckless,‘ or ‗grossly negligent‘ disregard of
Fourth Amendment rights,‖ Davis, 131 S. Ct. at 2427
(quoting Herring, 555 U.S. at 144), when they conducted the
warrantless installation and subsequent surveillance of the
GPS device upon Harry Katzin‘s automobile, but were
instead acting with ―an objectively ‗reasonable good-faith
belief‘ that their conduct [was] lawful.‖ Id. (quoting Leon,
468 U.S. at 909).

                          V.

        The majority holds otherwise, because, in its view, the
difference between the beepers used in Knotts and Karo and
the GPS device used in this case is ―one of kind, not degree,‖
Maj. Op. at 47 n.20, which makes all the ―differen[ce].‖
Furthermore, the majority chides reliance on Knotts, Karo,
and the relevant cases from our sister circuits because United
States v. Maynard, which held that prolonged GPS
surveillance was a search and did require a warrant, put the
officers on notice ―that such devices could ‗implicat[e] . . .
Fourth Amendment rights.‘‖ Maj. Op. at 54 n.24. I disagree
that these two considerations render the officers‘ conduct here
objectively unreasonable and sufficiently culpable so as to
incur the wrath of the exclusionary rule.

      Certainly, the technological difference between the
beepers of the 1980s and modern GPS devices is a
consideration to take into account in determining whether the
law enforcement officers were acting with an objectively




                               42
reasonable belief their actions were lawful. Modern ―GPS
units do not require police to follow the suspect visually, do
not allow the driver to detect tailing, and do not require an
expensive deployment of equipment and manpower.‖ United
States v. Hernandez, 

, 221 (5th Cir. 2011); see
also Maynard, 615 F.3d at 565 (opining that ―practical
considerations prevent visual surveillance from lasing [as]
long‖ as ―the use of the GPS in [that] case‖); Pineda-Moreno,
617 F.3d at 1126 (Kozinski, C.J., dissenting from denial of
rehearing en banc) (―[T]here‘s no hiding from the all-seeing
network of GPS satellites that hover overhead, which never
sleep, never blink, never get confused and never lose
attention.‖).

       Admittedly, this makes GPS devices different from the
beepers used in Knotts and Karo.            Beepers do not
independently determine their geographic location, but,
instead, ―emit[] periodic signals that can be picked up by a
radio receiver‖ within range of the beeper‘s radio transmitter.
See Knotts, 460 U.S. at 277. Beepers thus aid law
enforcement by assisting officers in visual surveillance of a
suspect, rather than doing the work of the officer altogether.
See Pineda-Moreno, 617 F.3d at 1124 (Kozinski, C.J.,
dissenting from the denial of rehearing en banc) (―[M]odern
[GPS] devices . . . can record the car‘s movements without
human intervention—quietly, invisibly, with uncanny
precision.‖).

       Notwithstanding these technological differences, ―[i]t
is the exploitation of technological advances that implicates
the Fourth Amendment, not their mere existence.‖ Karo, 468
U.S. at 712. ―Certainly, a GPS tracker is more capable than a
beeper, ‗but nothing inheres in the technology to take it out of




                              43
Knotts‘s holding.‘‖ Sparks, 711 F.3d at 66 (footnote omitted)
(quoting United States v. Cuevas-Perez, 

, 278
(7th Cir. 2011) (Flaum J., concurring)); see also United States
v. Andres, 

, 835 (5th Cir. 2013) (finding that
―any possible technological differences between a 1981
‗beeper‘ and the GPS device‖ insufficient because the two
devices‘ ―functionality [were] sufficiently similar‖); United
States v. Jones, 

, 768 (D.C. Cir. 2010) (Sentelle,
C.J., dissenting from the denial of rehearing en banc) (―There
is no material difference between tracking the movements of
the Knotts defendant with a beeper and tracking the Jones
appellant with a GPS.‖).

       Regardless of the technological differences, the GPS
reported to law enforcement no more information than that
which the officers could have obtained through pure visual
surveillance. Jesus-Nunez, No. 1:10-cr-00017-01, 

, at *3; see also Cuevas-Perez, 640 F.3d at 275
(dismissing as immaterial the increased accuracy of GPS
devices since ―real-time information is exactly the kind of
information that drivers make available by traversing public
roads‖). Every piece of data the GPS unit provided law
enforcement officers could have been otherwise obtained by a
police officer tracking Harry Katzin‘s vehicle on foot or in his
squad car on a public street;20 by an officer keeping an eye on

       20
          See California v. Greenwood, 

, 41
(1988) (―[T]he police cannot reasonably be expected to avert
their eyes from evidence of criminal activity that could have
been observed by any member of the public.‖); Texas v.
Brown, 

, 740 (1983) (plurality opinion) (―The
general public could peer into the interior of Brown‘s
automobile from any number of angles; there is no reason




                              44
the vehicle through use of a telescope or binoculars, or
utilizing a flashlight or spotlight so as to not lose the car
under the shadow of the night;21 or by an officer utilizing an
airplane or a helicopter to follow the vehicle along the public
roadways.22



[the officer] should be precluded from observing as an officer
what would be entirely visible to him as a private citizen.‖);
Katz v. United States, 

, 351 (1967) (―What a
person knowingly exposes to the public . . . is not a subject of
Fourth Amendment protection.‖).
       21
             See Brown, 460 U.S. at 739–40 (plurality opinion)
(―It is . . . beyond dispute that [the officer‘s] action in shining
his flashlight to illuminate the interior of Brown‘s car
trenched upon no right secured to the latter by the Fourth
Amendment.‖); United States v. Lee, 

, 563
(1927) (―For aught that appears, the cases of liquor were on
deck and, like the defendants, were discovered before the
motorboat was boarded. Such use of a searchlight is
comparable to the use of a marine glass or a field glass. It is
not prohibited by the Constitution.‖).
       22
          See Florida v. Riley, 

, 448–449, 451–52
(1989) (an officer ―circl[ing] twice over respondent's property
in a helicopter at the height of 400 feet‖ was not a search
because ―the police may see what may be seen from a public
vantage point where they have a right to be‖ (alteration and
internal quotation marks omitted)); California v. Ciraolo, 

, 213–14 (1986) (―Any member of the public flying
in this airspace who glanced down could have seen
everything that these officers observed.‖).




                                45
        The efficiency or efficacy of an officer‘s natural senses
often benefit from advances in technology. See Dow Chem.
Co. v. United States, 

, 231 (1986) (changes in
technology not only ―enhance[] industrial process, and indeed
all areas of life,‖ but ―they have also enhanced law
enforcement techniques‖). But ―[t]he mere fact that human
vision is enhanced‖ by some form of technological advance,
by itself, ―does not give rise to constitutional problems.‖ Id.
at 238; see also Silverman v. United States, 

, 513
(1961) (Douglas, J., concurring) (―[N]either should the
command of the Fourth Amendment be limited by nice
distinctions turning on the kind of electronic equipment
employed.‖). Again, ―[i]t is the exploitation of technological
advances that implicates the Fourth Amendment, not their
mere existence.‖ Karo, 468 U.S. at 712. ―Nothing in the
Fourth Amendment prohibit[s] the police from augmenting
the sensory facilities bestowed upon them at birth with such
enhancement as science and technology afforded them in this
case.‖ Knotts, 460 U.S. at 282. The information obtained
through use of the GPS was information otherwise observable
by the naked eye. See id. at 281–82. The GPS unit simply
made it easier for the law enforcement officers to obtain. See
id. at 284 (―Insofar as respondent‘s complaint appears to be
simply that scientific devices such as beepers enabled police
to be more effective in detecting crime, it simply has no
constitutional foundation.‖). And at the time the officers here
acted, it was indubitable that Harry Katzin lacked any
reasonable expectation of privacy in the information the GPS
unit was procuring. See id at 281.23 Thus, even taking into

       23
          Today, the question remains open as to whether
Jones effectually abrogated Knotts‘s conclusion that persons
lack any reasonable expectation of privacy in the information




                               46
consideration the technological difference between the
beepers used in Knotts and Karo and the GPS units used in
this case, the officers were clearly not ―exploit[ing]‖ GPS
technology in a way so as to put them on notice that their


the GPS unit was procuring. The only question answered in
Jones was whether a search had occurred through the
installation and subsequent use of the GPS device. Thus, the
Fourth Amendment implications of the information obtained
by the GPS surveillance, alone, were not discussed. Jones did
state that ―Knotts noted the ‗limited use which the
government made of the signals from [that] particular beeper;
and reserved the question whether ‗different constitutional
principles may be applicable‘ to ‗dragnet-type law
enforcement practices‘ of the type that GPS tracking made
possible [in that case].‖ Jones, 132 S. Ct. at 952 n.6 (citations
omitted). But Justice Scalia‘s opinion for the majority
refrained from altering Knotts‘s conclusion that ―the
information obtained—the location of the automobile
carrying the [beeper] on public roads . . .—had been
voluntarily conveyed to the public,‖ and was therefore not a
search. Id. at 951–52. Nonetheless, five justices wrote or
joined the concurring opinions in Jones, all of which seemed
to endorse the so-called ―mosaic‖ theory expressed in
Maynard—which would unequivocally limit the holding in
Knotts to apply in only short-term surveillance. See Orin
Kerr, The Mosaic Theory of the Fourth Amendment, 111
MICH. L. REV. 311, 326 (2012). This question does not need
to be answered today; but emphasizes the major shift caused
by Jones in Fourth Amendment law, and the vastly different
legal regime under which the law enforcement officers here
were acting.




                               47
actions were unconstitutional.24 See Cuevas-Perez, 640 F.3d
at 279–80 (Flaum, J., concurring) (opining before Jones that
―[t]he holding of Knotts is that a person has no expectation of
privacy in movements from one place to another on public

       24
           The majority concludes otherwise, alluding that my
preferred disposition would ―leave [persons] at the mercy of
advancing technology.‖ Maj. Op. at 48 n.20 (citing Kyllo v.
United States, 

, 35–36 (2001)). This case is
categorically distinct from Kyllo. In Kyllo, the officers
utilized technology to observe infrared radiation, which is
otherwise invisible to the naked eye. 533 U.S. at 29.
Furthermore, the officers utilized that technology in order to
determine the relative temperature of the interior of a home,
an area entitled to almost absolute protection under the Fourth
Amendment. Id. at 29–30; see also Florida v. Jardines, 

__, 

, 1414 (2013) (―[W]hen it comes to
the Fourth Amendment, the home is first among equals.‖). In
contrast, the use of the GPS device in this case provided
information otherwise observable by the naked eye on a
public street. What is more, although the Court found it
―foolish to contend that the degree of privacy secured to
citizens by the Fourth Amendment has been entirely
unaffected by the advance of technology,‖ Kyllo made much
of the fact that the technology used in that case was ―not in
general public use.‖ 533 U.S. at 33–34. Alternatively, GPS
technology is widespread, and one need look only on the
dashboard of his vehicle or the screen of his cellular
telephone to spot one. Kyllo‘s concerns, of course, arise in all
Fourth Amendment cases dealing with advanced technology.
But it is safe to say that those concerns are not implicated by
out facts.




                              48
roads; by its terms, the holding is indifferent to the
technology used to observe those movements‖).

       Nor does the existence of United States v. Maynard,

 (D.C. Cir. 2010) affect the officers‘ reasonable
belief that their conduct was lawful. First, the Maynard
holding was based on the fact that the GPS surveillance
conducted in that case lasted for four weeks, which allowed
law enforcement to obtain ―information not revealed by short-
term surveillance.‖ See Maynard, 615 F.3d at 562; Cuevas-
Perez, 640 F.3d at 274 (―[T]he Maynard court repeatedly
distinguished the surveillance at issue there from surveillance
during a single journey.‖). Conversely, the GPS tracking in
this case lasted for only two days, (see Appendix at 112–15,
143–50.), and Appellees make no argument that the
information obtained by the GPS device ―reveal[ed] more‖
about their personal lives ―than does any individual trip
viewed in isolation.‖ Maynard, 615 F.3d at 562.25 Besides,

      25
          The majority claims this is a distinction without a
point, because ―when the police attached their GPS device to
Harry Katzin‘s van, they had no way of knowing when the
next Rite Aid robbery would take place‖; thus characterizing
the GPS tracking here as ―a long-term surveillance project.‖
See Maj. Op. at 50 & n.22. But for purposes of whether a
Fourth Amendment violation occurred it matters not what law
enforcement officers could have done but what they did do.
See Dow Chem. Co., 476 U.S. at 238 n.5 (―Fourth
Amendment cases must be decided on the facts of each case,
not by extravagant generalizations. ‗[W]e have never held
that potential, as opposed to actual, invasions of privacy
constitute searches for purposes of the Fourth Amendment.‘‖
(alteration in original) (quoting Karo, 468 U.S. at 712)); cf.




                              49
―Knotts gave scant reason to think that the duration of the
tracking in that case was material to the Court‘s reasoning.‖
Sparks, 711 F.3d at 67.26



United States v. Jacobsen, 

, 122 (1984) (―The
concept of an interest in privacy that society is prepared to
recognize as reasonable is, by its very nature, critically
different from the mere expectation, however well justified,
that certain facts will not come to the attention of the
authorities.‖).
       26
          The Knotts Court did say, however, that ―if dragnet-
type law enforcement practices‖ such as ―twenty-four hour
surveillance of any citizen of this country . . . without judicial
knowledge or supervision,‖ ―should eventually occur, there
will be time enough then to determine whether different
constitutional principles may be applicable.‖ Knotts, 460
U.S. at 283–84. But merely acknowledging that ―different
constitutional principles may be applicable‖ does not imply
what those principles may be and how they impact the
relevant analysis. See Shelby Cnty. v. Holder, 

__,

, 2637 n.3 (2013) (Ginsburg, J., dissenting)
(―Acknowledging the existence of ‗serious constitutional
questions‘ does not suggest how those questions should be
answered.‖ (citation omitted)). Nonetheless, I seriously doubt
that the ―dragnet-type law enforcement practices‖ referred to
by the Knotts Court, whatever they may be, are akin to what
occurred in this case, where law enforcement officers had
evidence to suggest that Harry Katzin was a serious criminal;
evidence his attorney admitted at argument gave rise to
probable cause. (See Oral Arg. Trans. at 43:7–16.)




                               50
Furthermore, consider this hypothetical: Imagine, under facts
identical to our case, the D.C. Circuit‘s Maynard decision
was, instead, the only case holding that GPS use was not a
search and did not require a warrant. If, under those
circumstances, the officers claimed to rely only upon
Maynard for a reasonable belief that their conduct complied
with the Constitution, that consideration would weigh more
toward a finding of law enforcement culpability. But, here,
we are presented with the alternative, and Maynard was the
only holding (i.e., not a dissent or concurring opinion) from
any court at the time the officers executed the warrantless
GPS surveillance that considered their conduct illegal. As a
result, the fact that Appellees are pointing to Maynard as the
only case that said the law enforcement officers could not do
what they did is a consideration that weighs in the officers‘
favor.

                            ****

        Under the majority‘s rule, where law enforcement
officers engage in ―extrapolat[ion] [of] their own
constitutional rule,‖ or where officers ―assum[e] that their
own self-derived rule sanction[s] their conduct,‖ those
officers act with sufficient culpablity so as to justify
application of the exclusionary rule. Maj. Op. at 51. I agree
that ―[t]he justifications for the good-faith exception [may]
not extend to situations in which police officers have
interpreted ambiguous precedent.‖ Sparks, 711 F.3d at 67
(quoting Davis, 598 F.3d at 1267). But that is not the case
here, ―where new developments in the law have upended the
settled rules on which police relied.‖ Id. at 68.




                             51
       Before Jones, all but one federal court of appeals to
address the issue unequivocally concluded that Knotts, Karo,
and other relevant Supreme Court precedent sanctioned the
law enforcement conduct that occurred here. These Fourth
Amendment principles, upon which the law enforcement
officers relied in this case, were settled maxims of
constitutional jurisprudence, some of them governing law
enforcement conduct for decades. The majority, viewing this
case through Jones-colored lenses, rules with the benefit of a
hindsight that was unavailable to the officers here.

       United States v. Jones changed things; and changed
them in a way very few—if any at all—predicted. The
exclusionary rule does not require us to punish the law
enforcement officers here for failing to predict that sea
change.27 The District Court below put it quite aptly:


       27
         I have serious reservations about the implications of
the majority‘s ruling in this case. Nevertheless, I admit my
position might encourage some law enforcement officers to
bend and twist existing precedent and legal principles to their
breaking points. In some cases, law enforcement ―reliance‖
could be marginal at best.

       But I have confidence that courts are aptly suited to
discern the true ―good-faith actors‖ from the bad; and that, in
circumstances such as those presented in this case, we will be
able to definitively answer the question of whether law
enforcement officers were acting with objectively reasonable
good faith. Rulings that officers come up short will help
deter undesirable law enforcement conduct.




                              52
       [T]he Court hastens to emphasize that it has no
       concern that the prosecutorial and law
       enforcement personnel here were undertaking
       their work in this investigation and prosecution
       in a calculated or otherwise deliberately cavalier


        The majority recognizes that ―applying existing
precedential framework to subtle factual permutations is
something that police officers—and other law enforcement
personnel—do all the time.‖ Maj. Op. at 57 n.27. But while
insisting that its opinion does not ―curtail such practices,‖ the
majority punishes the law enforcement officers in this case
for performing that exact practice. There may not have been
a case from our Circuit or the Supreme Court specifically
detailing what the officers should have done in the particular
circumstances presented here. But there were cases from the
Supreme Court that came very close; close enough, in fact,
that some of our sister courts found them to be controlling as
precedents in situations similar to the case at bar.

       Obviously there is not enough time, history, or reporter
space to answer every single Fourth Amendment question.
As a result, the exclusionary rule has developed to provide a
remedy on the backend. Often the hurried judgments of an
officer, however well intentioned, simply do not comply with
constitutional rights. But as a matter of Fourth Amendment
policy, I would rather allow the officer more freedom in
performing his job—particularly where the answer to the
―appl[ication of] existing precedential framework to subtle
factual permutations‖ is so readily apparent as it was in this
case—than protect courts from overly burdensome
suppression motions. Ruling on suppression motions is part
of our job.




                               53
       or casual manner in the hopes of just meeting
       the outer limits of the constitutional contours of
       the Katzins‘ rights. Indeed, these actors could
       well profess surprise at the specific outcome of
       Jones.

United States v. Katzin, Crim. No. 11-226, 

, at *10 n.15 (E.D. Pa. May 9, 2012). Regardless of
this seemingly dispositive conclusion, the District Court
found, and the majority now affirms, that the exclusionary
rule requires suppression of the evidence obtained by such
non-culpable law enforcement conduct.

        Doing so renders the exclusionary rule a ―strict-
liability‖ regime, something which it emphatically is not. See
Davis, 131 S. Ct. at 2429. The exclusionary rule is ―a
‗prudential‘ doctrine,‖ id. at 2426 (quoting Scott, 524 U.S. at
363), which requires a ―rigorous weighing of [the] costs and
deterrence benefits,‖ id. at 2427, lest a ―guilty and possibly
dangerous defendant[] go[es] free,‖ Herring, 555 U.S. at 141.
As a society, we willingly swallow that ―bitter pill‖ when we
must. Davis, 131 S. Ct. at 2427. But under the circumstances
present in this case, I do not find the law enforcement conduct
to be ―sufficiently culpable‖ so that the benefit from deterring
that conduct ―is worth the price paid by the justice system,‖
John, 654 F.3d at 417, even if it might create a marginal
incentive for officers to ―err on the side of constitutional
behavior.‖ United States v. Johnson, 

, 561
(1982). Marginal deterrence is not the trigger of the
exclusionary rule, Herring, 555 U.S. at 141; law enforcement
culpability, and, thus, the opportunity for appreciable
deterrence is. Leon, 468 U.S. at 909; John, 654 F.3d at 417.
In consequence, because I find that the law enforcement




                              54
officers here lacked the requisite culpability in their actions so
as to justify application of the exclusionary rule, I respectfully
dissent from the majority‘s conclusion to the alternative. I
would reverse the District Court below.




                               55