PRECEDENTIAL

    UNITED STATES COURT OF APPEALS
         FOR THE THIRD CIRCUIT
                 ______

                   No. 17-1576
                     ______

        UNITED STATES OF AMERICA

                        v.

       WARREN CHARLES GREEN, IV,
                            Appellant
                ______

  On Appeal from the United States District Court
     for the Western District of Pennsylvania
               (3-13-cr-00016-001)
    District Judge: Honorable Kim R. Gibson
                     ______

            Argued October 23, 2017
Before: GREENAWAY JR., NYGAARD and FISHER,
                Circuit Judges.

              (Filed: July 25, 2018)
Lisa B. Freeland, Esq.
Christopher B. Brown, Esq.
Kimberly R. Brunson, Esq. [ARGUED]
Office of Federal Public Defender
1001 Liberty Avenue
1500 Liberty Center
Pittsburgh, PA 15222
                 Counsel for Appellant

Scott W. Brady, Esq.
Rebecca R. Haywood, Esq.
Michael L. Ivory, Esq. [ARGUED]
Office of United States Attorney
700 Grant Street, Suite 4000
Pittsburgh, PA 15219
                  Counsel for Appellee
______

                OPINION OF THE COURT
                        ______


FISHER, Circuit Judge.
        Following a traffic stop, police discovered
approximately twenty pounds of heroin in the trunk of the car
driven by Warren Charles Green, IV. Green appeals his
resulting conviction, claiming that the traffic stop was both
instigated and prolonged in violation of the Fourth
Amendment. Finding no constitutional violation on either
front, we will affirm the conviction.
                               I




                              2
                     A. Factual Background
        This case involves three separate traffic stops, all
performed by Pennsylvania State Trooper Michael Volk, that
are arguably relevant to Green’s constitutional claims. As a
drug interdiction officer, Volk’s duties largely consist of
traveling on the Pennsylvania Turnpike in an unmarked
cruiser to search for drugs, money, and weapons. Each of the
stops occurred on the Turnpike in the vicinity of Somerset,
roughly 70 miles east of Pittsburgh. The first stop involved
two men with no further direct connection to the case. The
latter two stops both involved Green. The Government argues
that information Volk obtained during the first stop helped
contribute to reasonable suspicion of Green’s criminal
activity during the final stop, which led to the heroin
discovery.
                          April 3, 2013
        Volk stopped a vehicle traveling eastbound on the
Pennsylvania Turnpike. This stop did not involve Green, but
rather two other men who, like Green, are black. The men had
a dog in their back seat. Volk’s stated reason for the stop was
for following too closely, but he suspected that the stopped
vehicle and another vehicle traveling close by were involved
in drug trafficking. The occupants stated that they were
traveling to Long Branch, New Jersey, in order to breed the
dog, which they described as an “American Bully.” Volk’s
computer was not working at the time, so he let the
individuals go with a verbal warning. Later that day, Volk
learned that at least one of the occupants was on federal
pretrial release for drug violations.
                          April 4, 2013
        At approximately 8 a.m. the next day, Volk
simultaneously pulled over two separate vehicles traveling
eastbound on the Turnpike. Again, Volk believed that the two



                              3
cars were travelling together and involved in drug trafficking.
The stated reasons for the stops were a license plate violation
and illegal window tinting. Both drivers denied knowing each
other. The first driver, a white male, informed Volk that he
was traveling to Baltimore for work. Green drove the second
vehicle and informed Volk that he was going to Philadelphia
to see family. When Volk asked Green how long he was
planning to stay in Philadelphia, Green initially responded, “I
don’t know. That all depends,” at which point Volk began to
speak over him, laughing, and asked, “You don’t have to get
back for work or anything?” Green explained that he owned a
barbershop, so he had a good amount of flexibility with
regard to the hours he worked. Nothing else was discussed
about the planned duration of Green’s trip and the
conversation diverted to other topics. A check of Green’s
license revealed that he had multiple prior arrests for drug and
weapon offenses, though Volk was unaware if Green had any
prior convictions.
        After several minutes, Volk brought Green to the rear
of Green’s vehicle and issued a warning for the window tint
violation. Green told Volk that he had only recently
purchased the vehicle and that the windows had been tinted
by the previous owner. Volk then told Green he could
continue on his way. As Green was walking back to the
driver’s side of his car, Volk asked him if there was anything
in the vehicle that should not be there. Green responded that
there was not. Volk then asked for Green’s consent to search
the vehicle and Green acceded, eventually signing a waiver.
Volk searched Green’s vehicle, including the engine
compartment, for roughly twelve minutes and did not
discover any contraband. In fact, Green did not have any
luggage or baggage of any kind in his vehicle. While
conducting the search, Volk detected the smell of raw




                               4
marijuana in the trunk compartment and noticed that the trunk
liner was pulled back. Volk did not discuss any of these
observations with Green. Following the search, Volk allowed
Green to continue on his way. Volk also received consent to
search the other vehicle and similarly uncovered no
contraband.
                          April 5, 2013
       At approximately 10 a.m. the following day, Volk was
removing debris on the side of the Turnpike and noticed
Green’s vehicle traveling westbound. By his own admission,
Volk decided at this point that he would try to find a reason to
stop Green. Volk followed Green and ascertained his speed
by “pacing” Green’s vehicle. When pacing, an officer finds
the speed at which his vehicle remains equidistant from the
target vehicle in order to assess the target vehicle’s speed. See
75 Pa. Cons. Stat. § 3368 (requirements for pacing). Here,
Volk followed one to two-tenths of a mile behind Green’s car
for a distance of roughly six-tenths of a mile. The speed limit
on that portion of the Turnpike was 65 miles per hour. Volk
determined that Green was traveling 79 miles per hour and
pulled him over. After walking up to Green’s window, Volk
feigned surprise, saying, “You again!” in a light-hearted
manner. When Volk noted that he pulled Green over for
speeding, Green apologized and said that he had left the
cruise control on while going down a hill. As Green was
gathering his license and registration, he asked Volk, “How
you doin’ today?” Volk replied and then asked Green how he
was doing, to which Green responded, “I can’t complain. I
got a dog, so.” Volk then observed a dog in the back of
Green’s vehicle and believed it was—or at least resembled—
the dog from the April 3 stop. Volk asked Green why he had
returned from Philadelphia after only one day, despite saying
the day before that he would be there for “a couple days.” As



                               5
quoted above, Green did not actually say he would be gone “a
couple days” during the earlier stop, but that was how Volk
remembered the previous day’s conversation. In any event,
Green explained that he was returning from Philadelphia
because his daughter had just broken her leg, so he had to
hurry back to take care of her. This conversation lasted about
forty seconds.
        After returning to his cruiser with Green’s license and
registration, Volk immediately called a colleague to fill him
in on the events dating back to April 3. This phone call lasted
roughly two minutes and had a decidedly jocular tone. Volk
had already requested backup prior to his initial conversation
with Green and waited in his vehicle for its arrival. It is
unclear whether Volk also requested a canine unit at this time.
About eight minutes after the end of his phone call, and with
backup not having arrived, Volk called Green to the rear of
Green’s vehicle.1 Volk again issued Green a warning and
Green struck up a lengthy conversation about his daughter’s
injury. During this exchange, both Volk and Green stood at
the rear of Green’s vehicle observing the dog through the
back window. Green described the dog’s breed as a “Cane
Corso” or “Presa Canario,” and related that he had bought the
dog from a kennel somewhere outside of Philadelphia, though
he could not recall the name of the exact town. As had
happened the day before, Volk indicated that Green was free
to leave, but as Green was walking back to the driver’s door,
Volk again asked if he could search Green’s vehicle. This
time, Green apologized and declined, explaining that he was
in too much of a hurry. Volk then instructed Green to wait in
his car until further notice.

      1
        The record does not reveal why Volk chose not to
wait any longer for backup.



                              6
        After approximately fifteen minutes, during which
there was no meaningful interaction between Volk and Green,
a canine unit arrived. Green was taken out of his vehicle and
told to take his dog with him to a safe distance away from the
police dog.2 A canine sweep of the car resulted in an alert for
drugs in the trunk. Based on this evidence, Volk obtained a
search warrant a few hours later. A search of Green’s trunk
revealed a duffel bag containing roughly 1,000 bricks of
heroin weighing nearly 20 pounds.
                     B. Procedural History
        Green was charged with possession with intent to
distribute one kilogram or more of heroin. Green filed a
motion to suppress the heroin as obtained in violation of the
Fourth Amendment. The District Court held an evidentiary
hearing nearly three years after the original stop, in which
Volk testified as the only witness. After the District Court
denied Green’s motion, he pled guilty to the single count,
preserving the constitutional issues for appeal. Green was
sentenced to 120 months of imprisonment—the mandatory
minimum—followed by five years of supervised release.
                               II
        The District Court exercised jurisdiction under 28
U.S.C. § 3231, and this Court exercises jurisdiction under 28
U.S.C. § 1291. On an appeal of a denial of a motion to
suppress, the District Court’s factual findings are reviewed
for clear error and its legal determinations are subject to

      2
        At this point, Volk performed a patdown of Green.
Green’s claim that this patdown was unconstitutional is
without merit. See United States v. Murray, 

,
393 (3d Cir. 2016) (holding that a suspect’s connection with
drug dealing supports reasonable suspicion that he is armed
and dangerous).



                              7
plenary review. United States v. Lewis, 

, 237 (3d
Cir. 2012). We will affirm the District Court’s denial of
Green’s motion to suppress. Although our reasoning differs in
some respects from that of the District Court, we may affirm
on any ground supported by the record. Tourscher v.
McCullough, 

, 240 (3d Cir. 1999).
                                III
        Green’s constitutional claims require us to answer
several discrete questions. First, we must assess whether the
District Court erred when it ruled that the final traffic stop on
April 5 was supported by reasonable suspicion of a traffic
violation. If there was no error, we must proceed to determine
whether the District Court was also correct in its
determination that the stop was conducted in a constitutional
manner. Green argues that the stop was prolonged in violation
of the Fourth Amendment. To address this claim, we must
first decide when the stop was extended, and then determine
whether, at that point, the extension was justified by a
reasonable suspicion of criminal activity.
                 A. Initiation of the Traffic Stop
        We turn first to Green’s contention that the April 5
stop was initiated in violation of the Fourth Amendment.
Traffic stops are classified as a type of Terry stop, and may be
initiated based on a reasonable suspicion that a traffic
violation has occurred. Navarette v. California, 

, 1686 (2014); see United States v. Delfin-Colina, 

, 396–97 (3d Cir. 2006) (adopting reasonable
suspicion, not probable cause, as the applicable standard).
Here, Volk paced Green’s vehicle in compliance with the
relevant Pennsylvania statute and estimated his speed at 79
miles per hour, 14 miles per hour above the posted limit.
Conceding these facts, Green nonetheless argues that the
distance at which Volk conducted the pacing—between one



                               8
and two-tenths of a mile—was too great to allow for a reliable
estimate of Green’s speed. We disagree.
       When pacing, the key requirement is maintaining a
consistent distance with the target vehicle. At the suppression
hearing, Volk testified that he was able to maintain a constant
interval between himself and Green. The District Court found
that Green’s vehicle was some distance from Volk’s, but not
so far that Volk would have been unable to determine if the
interval between the two was increasing, decreasing, or
remaining constant. The dashboard camera footage from
Volk’s cruiser shows that this factual finding is not clearly
erroneous. Our confidence in Volk’s assessment is further
supported by the fact that Green was traveling significantly
faster than the speed limit allowed. Logically, the more
excessive a driver’s speed, the less precise a measurement
must be to establish reasonable suspicion that the driver is
speeding at least to some degree. See United States v.
Sowards, 

, 591–92 (4th Cir. 2012). The
operative question is whether Volk had a reasonable
suspicion that Green was speeding, not whether Volk could
determine Green’s exact speed. The District Court did not err
in concluding that Volk had a reasonable suspicion that Green
was speeding, so the stop was justified.3
                B. Extension of the Traffic Stop
       We next consider whether the April 5 traffic stop,
though “lawful at its inception,” was unreasonably extended

       3
         Green’s argument that the stop was pretextual is both
true and immaterial. It has long been axiomatic that “a traffic-
violation arrest . . . [is not] rendered invalid by the fact that it
was ‘a mere pretext for a narcotics search.’” Whren v. United
States, 

, 812–13 (1996) (quoting United States v.
Robinson, 

, 221 n.1 (1973)).



                                 9
in violation of the Fourth Amendment. Illinois v. Caballes,

, 407 (2005). An unreasonable extension occurs
when an officer, without reasonable suspicion, diverts from a
stop’s traffic-based purpose to investigate other crimes.
Rodriguez v. United States, 

, 1615 (2015).
There is no dispute that the April 5 traffic stop was extended
to facilitate a canine sniff for drugs. What is disputed,
however, is when this extension occurred, and whether, at
that moment, Volk possessed reasonable suspicion in order to
justify the extension. In light of Rodriguez, we must first
determine when the stop was “measurably extend[ed].” 

v. Johnson, 

, 333 (2009)).
After determining when the stop was extended—the
“Rodriguez moment,” so to speak—we can assess whether the
facts available to Volk at that time were sufficient to establish
reasonable suspicion that Green was involved in drug
trafficking.
        As subsequent cases in our sister Circuits have
demonstrated, the Rodriguez rule is far easier to articulate
than to apply, and we now find ourselves facing a similar
difficulty. We ultimately conclude that Rodriguez does not
provide a clear answer for pinpointing the April 5 “Rodriguez
moment.” In light of such uncertainty—and solicitous of
Green’s Fourth Amendment rights—we will err on the side of
caution and assume the earlier of the two plausible
“Rodriguez moments” from which to assess reasonable
suspicion. Because Volk did indeed possess reasonable
suspicion at this earlier point, Green suffered no
constitutional injury in the course of the traffic stop.
                    The Rodriguez Decision
        Prior to Rodriguez, the Supreme Court held in
Caballes that a “dog sniff conducted during a . . . lawful
traffic stop” does not violate the Fourth Amendment as long



                               10
as the sniff does not result in the stop being “prolonged
beyond the time reasonably required to complete” its traffic-
based 

, 407. Following Caballes,
lower courts disagreed over whether a de minimis extension
of a traffic stop to allow time for a sniff would pass
constitutional muster. 

(comparing cases). Rodriguez answered this question with a
clear “no,” holding that, absent reasonable suspicion, any
“unrelated inquiries [that] measurably extend the duration of
[a] stop” are unlawful. 

(alterations added and
omitted) (quoting 

). In describing
what inquiries qualify as “unrelated,” Rodriguez drew a
distinction between “ordinary inquiries incident to” a traffic
stop, 

543 U.S. at 408), which serve the
purpose of enforcing the traffic code, and other measures
aimed at detecting criminal activity more generally. Actions
like “checking the driver’s license, determining whether there
are outstanding warrants against the driver, and inspecting the
automobile’s registration and proof of insurance” are in the
former category of inquiries incident to a traffic stop. 

sniff, being obviously focused on the enforcement of
drug—not traffic—laws, falls in the latter category and
cannot, therefore, be performed in a manner that extends the
duration of the stop absent reasonable suspicion. 

of determining when a traffic stop is
“measurably extended” is more difficult than Rodriguez’s
language might suggest. This difficulty stems, at least in part,
from the particular facts of both Caballes and Rodriguez. In
Caballes, the trooper making the stop radioed dispatch to
report his actions. This transmission happened to be
overheard by a drug interdiction officer, who immediately
traveled to the scene and conducted the dog sniff before any
citation had been issued. 

. In




                              11
Rodriguez, by contrast, the officer who initiated the stop
already had a drug dog in his 

. For
safety reasons, however, he issued a warning for speeding and
then waited for backup to arrive before conducting the dog
sniff. 

The Court declared the former stop
constitutional and the latter not. Neither case directly
addressed what pre-citation conduct might constitute an
impermissible extension.
        Justice Alito, dissenting in Rodriguez, criticized the
Court’s decision as “impractical[] and arbitrary,” and
lamented that the constitutional question appeared to turn,
“not [on] the length of the stop, but simply . . . the sequence
in which [the officer] chose to perform his 

, 1624 (Alito, J., dissenting). The majority disclaimed
this reading of its opinion, stating that “[t]he critical question
. . . is not whether the dog sniff occurs before or after the
officer issues a ticket . . . but whether conducting the sniff
‘prolongs’—i.e., adds time to—‘the stop’” 

(majority opinion). On this “critical question,” however,
Rodriguez’s language can be interpreted in a variety of ways.

an extension as anything that “adds time to,”

extend[s],” 

a stop, the Court
seems to imply that nearly anything an officer does outside
the valid, traffic-based inquiries will be unconstitutional. Yet,
other language in the opinion suggests a more forgiving
approach toward non-traffic-based actions. This ambiguity is
brought to the fore with a pair of adjoining sentences: “An
officer . . . may conduct certain unrelated checks during an
otherwise lawful traffic stop. But . . . he may not do so in a
way that prolongs the stop . . . .” 

Left
unexplained is how a police officer could possibly perform
multiple tasks simultaneously without adding any time to a
stop. While the majority makes clear that, contra Justice




                               12
Alito, sequence is not dispositive, 

Rodriguez
provides less clarity regarding what exactly is dispositive
when evaluating an officer’s pre-citation conduct.
        In a more general sense, Justice Alito’s concern was
that the Court’s attempt to craft a clear rule—no measurable
extensions—was impractical in light of the factual complexity
inherent in traffic stops. 

(Alito, J., dissenting). For
this reason, Justice Alito favored a more flexible
reasonableness standard to better account for the practical
realities of traffic stops, and warned that the Court’s ruling
would invite arbitrary and unpredictable results. 

A survey of post-Rodriguez appellate decisions reveals that
Justice Alito’s concerns were prophetic. The Rodriguez rule,
though clear in its formulation, has proved less precise where
the rubber meets the road.
                    Post-Rodriguez Decisions
        In several recent decisions, our sister Circuits have
adopted starkly divergent interpretations of Rodriguez.
Several have applied Rodriguez’s language quite rigidly,
holding that any diversion from a stop’s traffic-based mission
is unlawful absent reasonable suspicion. In United States v.
Gomez, for example, an officer stopped a vehicle for speeding
and running red lights. 

, 82 (2d Cir. 2017). When
the officer first approached the vehicle, the driver asked the
officer why he had been stopped, and the officer responded
that he was conducting a heroin investigation and that he had
observed the driver commit numerous traffic violations. 

Circuit determined that, by referencing the drug
investigation, the officer unconstitutionally detoured from the
traffic-based mission of the stop “[f]rom the moment” the
conversation began. 

In United States v. Evans, an
officer initiated a traffic stop and conducted a vehicle records
check, a license check, and an outstanding warrants check, all



                                13
of which came back clean. 

, 782–83 (9th Cir.
2015). One of these checks, however, revealed that the
stopped driver had a felony record. 

Accordingly,
the officer requested a check to verify that the driver was
properly registered at the address that he had provided. 

Circuit ruled that, while the first two checks were
permissible, the ex-felon registration check, not being directly
relevant to the traffic stop, unconstitutionally extended the
stop under Rodriguez. 

        Other Circuits have applied Rodriguez more leniently,
evaluating police actions by something more akin to a
reasonableness standard. In United States v. Collazo, the
Sixth Circuit found no constitutional violation because “most
of the questions” asked by the officer were related to the
traffic stop, “and none of them extended the traffic stop
beyond a reasonable time.” 

, 257–58 (6th Cir.
2016) (citing 

), cert. denied, 

(2016). More categorically, the Seventh Circuit
held in United States v. Walton that “[i]t was permissible for
[the sole officer on-scene] to ask [the driver and passenger]
questions unrelated to the traffic violations,” 

,




                              14
687 (7th Cir. 2016), cert. denied, 

(2016),
which undoubtedly extended the stop.4
        As these examples demonstrate, Caballes and
Rodriguez are difficult to apply beyond their facts, which has
resulted in inconsistent application in the lower courts.
Where, as in the present case, an officer arguably prolongs a
traffic stop before issuing a citation, these precedents serve as
an uncertain guide. What we know is that an officer may
“conduct certain unrelated checks,” but not “in a way that
prolongs the stop.” 

.
                       Applying Rodriguez
        This case presents many of the same ambiguities
highlighted above. There can be no doubt that Volk
measurably extended the traffic stop when, after issuing
Green a warning citation, he instructed Green to wait in his
car indefinitely. The key question is whether the stop was
measurably extended at an earlier point—that is, whether the
“Rodriguez moment” instead occurred when Volk returned to
his vehicle after his brief initial conversation with Green and
made an unrelated phone call to his colleague. If it did, then
nothing later in the stop can inform our reasonable suspicion


       4
        Even in traffic stop cases where courts have found no
Fourth Amendment violations, several dissenting opinions
have voiced the more restrictive interpretation of Rodriguez.
See United States v. Murillo-Salgado, 

, 419 (8th
Cir. 2017) (Kelly, J., dissenting) (arguing that “even brief[]”
questioning unrelated to the traffic stop must be supported by
reasonable suspicion); United States v. Hill, 

,
385 (4th Cir. 2017) (Davis, J., dissenting) (arguing that
“every minute” an officer spent seeking to confirm a
passenger’s identity unreasonably prolonged the traffic stop).



                               15
analysis. This includes, most significantly, the conversation
that occurred when Volk issued the citation to Green.
         Under a restrictive reading of Rodriguez, it seems clear
that Volk’s actions following the initial conversation with
Green, particularly the phone call to his colleague, added time
to the traffic stop and constituted an extension. See 

–91. This phone call was focused on Volk’s
suspicions about drug trafficking, not speeding. At the
suppression hearing, Volk conceded that, by the time he made
this call, he was intent on searching Green’s vehicle and no
longer concerned with the moving violation.5
         On the other hand, there are sound reasons in favor of
the more lenient approach followed by several Circuits. To
start, this short phone call, though unrelated to the traffic stop,
was not shown to have measurably prolonged the stop, which
took little more than ten minutes from its inception to the
issuance of the warning. Other courts have found that phone
calls requesting canine assistance are not measurable
extensions, United States v. Hill, 

, 384 (4th Cir.
2017), though this conclusion is far from obvious under the
reasoning of Rodriguez. Additionally, at the time Volk made
the phone call he was apparently still waiting for backup,

       5
          When asked about this portion of the stop, Volk
testified as follows:
Q. At this point you are focused on “I am searching this car,
right?”
A. I would like to, yes.
Q. This is not a moment about giving a warning for a
speeding ticket, right?
A. Correct.

App. 193.



                                16
which raises its own set of considerations. Rodriguez
acknowledged the danger to police officers inherent in traffic
stops, and found no constitutional injury where an officer
takes “negligibly burdensome precautions in order to
complete his [traffic] mission 

. By
contrast, “safety precautions taken in order to facilitate”
investigation of other crimes are not justified as part of a
routine traffic stop. 

request for backup
was motivated by safety concerns inherent to the traffic stop,
then any actions taken while waiting for backup to arrive,
including the phone call, did not add to the “time reasonably
required to complete the mission.” 

(alteration
omitted) (quoting 

). Rodriguez
would seem to suggest that the validity of Volk waiting for
backup turns on his motivation for making the request—
traffic-based or otherwise—but even this inquiry strikes us as
rather arbitrary. We doubt very much that Volk’s motivation
can be distilled to a single concern rather than a hazy
constellation of factors confronting an officer in such a
situation. Of course, Volk ultimately chose not to wait for
backup to arrive before reengaging with Green, which adds
still greater complexity to the analysis.
        In light of the uncertainty in applying Rodriguez to the
present facts, we believe that the prudent course is to err on
the side of caution and proceed on the assumption—not
conclusion—that the “Rodriguez moment” occurred
immediately after Volk’s initial conversation with Green.
Accordingly, we will assess reasonable suspicion based only
on the facts known to Volk at that time. Because we conclude
that Volk did possess reasonable suspicion at this moment,
there will be no need to address the possible implications of a
later “Rodriguez moment.”




                              17
                    C. Reasonable Suspicion
        We now ask whether, at our assumed “Rodriguez
moment,” Volk possessed reasonable suspicion of criminal
activity. In speaking of reasonable suspicion, our precedents
describe more than define the term, which the Supreme Court
has characterized as an “elusive concept.” United States v.
Cortez, 

, 417 (1981). Reasonable suspicion is
more than “a mere hunch . . . [but] considerably less than . . .
a preponderance of the evidence, and obviously less than . . .
probable cause.” 

(internal
quotation marks and citations omitted) (quoting 

; and Terry v. Ohio, 

, 27 (1968)).
Reasonable suspicion requires only “‘a particularized and
objective basis’ for suspecting . . . criminal activity,” Ornelas
v. United States, 

, 696 (1996) (quoting 

–418), and should not be derived from
characteristics common to the “vast majority of innocent”
individuals, Karnes v. Skrutski, 

, 494 (3d Cir.
1995).
        In applying this standard, courts invoke several
common themes. First, reasonable suspicion must always be
evaluated under the totality of the circumstances. 

. Accordingly, courts have consistently refused to
adopt per se rules declaring a particular factor sufficient or
insufficient to establish reasonable suspicion. See Illinois v.
Wardlow, 

, 126–27 (Stevens, J., dissenting)
(agreeing with the Court’s rejection of a per se rule regarding
flight from police). Second, when assessing the totality of the
circumstances, courts recognize the particular ability of law
enforcement officers, based on training and experience, “to
make inferences from and deductions about the cumulative
information available to them that ‘might well elude an
untrained person.’” United States v. Arvizu, 

, 273



                               18
(2002) (quoting 

). Third, and
consistent with the totality of the circumstances approach,
reasonable suspicion cannot be defeated by a so-called
“divide-and-conquer” analysis, whereby each arguably
suspicious factor is viewed in isolation and plausible,
innocent explanations are offered for each. District of
Columbia v. Wesby, 

, 589 (2018). In Terry
itself, the Court found there was reasonable suspicion to
justify the temporary seizures even though each factor relied
on by the officer, viewed in isolation, might have seemed
perfectly innocent. 

(citing 

).
                    The Prior Stop and Search
          Applying this standard to the present case, our first
challenge is determining the constitutional significance of the
first encounter between Green and Volk on April 4. During
that stop, Green consented to a search of his vehicle, which
failed to uncover any contraband. The Government argues
that the unsuccessful nature of the April 4 search is
essentially irrelevant to the question of reasonable suspicion
on April 5. Green counters that, because he consented to the
April 4 search and was found free of contraband, no
information from the search could be used to support
reasonable suspicion on April 5. Essentially, Green argues
that the April 4 search gave him a clean slate moving
forward. In support, Green cites United States v. Peters, 

(10th Cir. 1993), which likewise included multiple
traffic stops in relatively quick succession. The District Court,
perhaps seeking to avoid this thorny issue, purported to
conduct an independent analysis of the April 5 facts alone. In
reality, however, the District Court’s analysis incorporated
several facts from the preceding two days. For instance, the
District Court found Green’s travel on April 5 to be



                               19
suspicious, but could have only reached this conclusion by
relying on Green’s April 4 statements about his travel plans.
        The present case is easily distinguishable from Peters.
There, an officer pulled over the defendant and his passenger
for erratic driving in a rented moving truck. The officer
suspected that Peters was transporting drugs, and received
consent to search his truck. This search failed to uncover any
contraband and the officer sent Peters on his way. Concerned
that his search had been inadequate, the officer radioed his
headquarters about the situation. This led to Peters again
being pulled over a few hours down the road, at which point a
different officer uncovered evidence that Peters was present
in the country illegally. The Tenth Circuit ruled that this
evidence should have been suppressed because the second
stop was unconstitutionally premised on the same factors that
justified the initial stop. 

        In Green’s case, roughly twenty-six hours elapsed
between the two traffic stops, as opposed to the four or five
hour interval in Peters. In addition, the nature of Green’s
suspected crime—drug trafficking—made it entirely plausible
for Green to have acquired drugs during the intervening time
period. In Peters, by contrast, the officers all but knew that
the suspect had driven uninterrupted between the two traffic
stops. 

In fact, they relied on this assumption to
predict Peters’ location for the second stop. 

could not have reasonably suspected that Peters acquired
contraband between the two stops. Nor was that the point; the
second search was simply a redo of the first. Finally, in Peters
there was no independent basis for making the second traffic
stop. 

Here, Green’s speeding provided a
legitimate justification for the April 5 stop.
        Given these substantial differences, we see no
reason—constitutional or otherwise—to follow Peters and



                              20
exclude from our analysis information gained during the
April 4 stop. It bears repeating: reasonable suspicion is based
on the totality of the circumstances, i.e., “the whole picture.”

. Categorically excluding a large
swath of evidence is quite the opposite of considering “the
whole picture.” Incidentally, this case illustrates that the
totality of the circumstances approach does not inherently
benefit either side. For instance, although our analysis
appropriately considers the fact that Volk detected the smell
of raw marijuana emanating from Green’s trunk on April 4,
we also consider as strong evidence the fact that Green’s
vehicle was searched and contained no contraband. “[T]he
ultimate touchstone of the Fourth Amendment is
‘reasonableness’ . . . .” Brigham City, Utah v. Stuart, 

, 403 (2006) (quoting Flippo v. West Virginia, 

, 13 (1999) (per curiam)). In our view, a reasonable
officer in Volk’s position, rather than excluding certain
evidence, would consider all of the facts available to him and
accord each its due weight. In evaluating his actions, the
Constitution requires that we do likewise.
                 Reasonable Suspicion Factors
        As noted above, when evaluating reasonable suspicion
a court’s task is to assess the situation as a whole.
Nevertheless, in explaining our analysis it will often be
beneficial, for the sake of clarity, to explain each factor’s
relative weight in establishing reasonable suspicion. In
accordance with our Rodriguez analysis, we will only
consider those facts known to Volk at the time he completed
his conversation with Green at the beginning of the April 5
stop. We conclude that Volk possessed a reasonable suspicion
that Green was engaged in criminal activity. This conclusion
is based on three primary factors: (1) Green’s misleading




                              21
statements regarding his travel, (2) the smell of marijuana in
Green’s trunk, and (3) Green’s criminal history.6
1. Green’s Misleading Statements
       Shortly after being stopped on April 4, Green related
to Volk that he was traveling to Philadelphia to visit family.
Volk asked Green how long he was staying, to which Green
responded, “I don’t know. That all depends.” Volk
immediately began to laugh and, speaking over Green, asked
“You don’t have to get back for work or anything?” Green
responded that he was a barber, so his hours were fairly
flexible. Roughly twenty-six hours later, Volk pulled Green
over again as he returned from Philadelphia to Pittsburgh.
Based on these facts, the District Court concluded that
Green’s statements “about his travels to Philadelphia were
inconsistent and contradictory,” and thus contributed to
Volk’s reasonable suspicion.
       As an initial matter, we note that nothing in Green’s
statement to Volk on April 4 was logically inconsistent with
his April 5 return. Green’s statement indicated that his trip
was for an indeterminate length of time, which obviously
does not foreclose a one-day turnaround. Contradictory or
inconsistent statements may contribute to reasonable
suspicion, United States v. Givan, 

, 459 (3d Cir.
2003), but an incomplete statement is not necessarily
contradictory or inconsistent. For all we know, Green’s
complete, uninterrupted statement would have been, “I don’t
know. That all depends. Probably tomorrow, but maybe the
next day.” The fact that Green did not provide a full statement


      6
        Because these factors were sufficient to establish
reasonable suspicion, we will not analyze what, if any,
inferences could be drawn from the dog in Green’s car.



                              22
about his travel plans limits, but does not defeat, our reliance
on this factor.
        Though not strictly contradictory, Green’s statements
concerning his travel were sufficiently confusing so as to
meaningfully contribute to reasonable suspicion. While not
logically irreconcilable with his earlier statement, Green’s
travel was nonetheless suspicious. See United States v.
Benoit, 

, 285–86 (3d Cir. 2013) (premising
reasonable suspicion on inconsistent statements regarding the
purpose and destination of voyage). In the context of a cross-
state trip to visit family for the first time in a while, the
answer “I don’t know. That all depends,” is not how someone
would normally characterize the duration of a trip that could
possibly last only a few hours. More to the point, we cannot
say that Volk was unreasonable in believing that Green’s
April 4 statement was at least in tension with an April 5
return.
        In our mind, however, the more significant suspicion
arose, not from Green’s quick turnaround, but his own
statements on April 5. While Green was looking for his
license and registration at the beginning of the April 5 stop,
Volk asked him how he was doing and Green replied, “I can’t
complain. I got a dog, so.” Only after Volk alluded to their
conversation the day before—“I thought you were staying out
a couple days?”—did Green say he needed to rush back to
Pittsburgh because of his daughter’s broken leg.7 Volk was
justified in viewing Green’s shifting statements with
mounting skepticism. If it was true that Green’s family visit

       7
         The fact that Green did not challenge Volk’s
presumption regarding the intended duration of his trip
further mitigates our concern over Volk interrupting Green on
April 4.



                              23
had been cut short due to his daughter suffering a serious
injury, it is hard to imagine him responding to Volk’s
question—“How are you?”—with such a blasé answer—“I
can’t complain. I got a dog, so.” Moreover, Green had already
been informed that he was stopped for speeding, so it is
highly suspicious that he would not immediately offer his
daughter’s purported injury as an explanation for his rushing
home. Instead, Green’s initial explanation for speeding was
simply that he had left his cruise control on while going down
a hill. Green’s puzzling responses provided a reasonable basis
to believe that he was lying about his travels and contributed
to Volk’s reasonable suspicion of illegal activity.
2. The Smell of Marijuana
        During the consensual search of Green’s car on April
4, Volk detected the smell of raw marijuana in the trunk. Volk
was unable to locate the source of the smell, and the car was
otherwise free of contraband. “It is well settled that the smell
of marijuana alone . . . may establish not merely reasonable
suspicion, but probable cause.” United States v. Ramos, 

, 308 (3d Cir. 2006). Green, however, argues that the
unsuccessful search on April 4 eliminated any probative value
of the odor. We disagree. While the fact that no marijuana
was found on April 4 is certainly a relevant consideration, it
does not preclude our—or Volk’s—consideration of this
evidence in support of reasonable suspicion on April 5.
        The odor of marijuana in a car “can ‘be evidence of the
most persuasive character,’” 

n.5
(quoting Johnson v. United States, 

, 13 (1948)),
and is not an attribute shared by “a very large category of
presumably innocent travelers,” Reid v. Georgia, 

, 441 (1980) (per curiam). The absence of actual
marijuana on April 4 mitigates, but does not eliminate, the




                              24
probative value of this evidence.8 We agree with the
reasoning in Peters that, having conducted a prior search, the
officer could not justify a subsequent search absent additional

–23. But here, the April 5 stop was
independently justified and there was additional evidence to
support reasonable suspicion. In this context, we find no basis
in law or logic to prohibit consideration of the marijuana odor
merely because Green was not transporting drugs the day
before. Reasonable suspicion must be grounded in “the
factual and practical considerations of everyday life on which
reasonable and prudent men, not legal technicians, act.”
Brinegar v. United States, 

, 175 (1949). The
smell of marijuana is one such “practical consideration”
familiar to an officer with Volk’s experience in the field. The
Fourth Amendment does not demand the kind of cognitive
contortions that would be required for Volk to ignore highly
probative evidence of drug activity in deciding whether he
had reasonable suspicion to extend the stop. Volk was




      8
         Our analysis would be different if, for example, Volk
had seen something he believed to be marijuana but turned
out to be some other leafy substance. See 

. In that situation, later investigation would have
“exhausted” the validity of the earlier suspicion. 

. Here, the smell of marijuana suggested that
Green had recently transported drugs. The absence of drugs at
any particular moment in no way foreclosed this inference.



                              25
justified in relying on this odor as evidence of criminal
activity on April 5.9
3. Green’s Criminal History
        During the April 4 stop, Volk conducted a records
check and discovered that Green had multiple prior arrests for
drug and firearm violations. Volk did not learn how those
arrests were ultimately resolved or whether Green had any
convictions. Though a criminal record, much less an arrest
record, is not sufficient to establish reasonable suspicion, it is
a valid factor. United States v. Mathurin, 

, 177
(3d Cir. 2009). As we have previously noted, “the use of prior
arrests and convictions to aid in establishing probable cause is
not only permissible, but is often helpful.” United States v.
Conley, 

, 1207 (3d Cir. 1993) (citations omitted)
(collecting cases). This utility is enhanced when the prior
offenses relate to the crime being investigated. 

the other factors already discussed, Volk was amply
justified in considering Green’s drug arrests in assessing
reasonable suspicion of drug trafficking on April 5.
                                IV

       9
         Following oral argument, Green brought to our
attention a study raising questions about the reliability of
individuals’ ability to detect marijuana based on odor.
Appellant Letter of Oct. 30, 2017 (citing Richard L. Doty,
Thomas Wudarski, David A. Marshall and Lloyd Hasting,
Marijuana Odor Perception: Studies Modeled From
Probable Cause Cases, 28 Law and Human Behavior 223,
224 (2004)). While interesting, the study’s tentative
conclusions do not provide a sufficient basis for us to
overturn the District Court’s factual finding that “a smell of
raw marijuana was emanating from the trunk area” of Green’s
car. App. 8.



                               26
        Stepping back from these individual factors and
considering the “whole picture,” our question remains a fairly
straight forward one. After the conversation at the start of the
April 5 traffic stop, did Volk possess reasonable suspicion
that Green was engaged in criminal activity? At that moment,
Volk reasonably believed that Green had provided several
misleading statements about his travel, he knew that Green’s
trunk carried the odor of marijuana, and he knew that Green
had several prior arrests for drug and firearm violations. This
evidence of criminal activity was tempered by the fact that,
only one day prior, Green consented to a search of his
vehicle, which was found free of contraband. Reasonable
minds may disagree over the extent to which the results of
this search counteracted the various indicia of criminality, but
that is precisely the point. Whatever the effect of the prior
search, it was not so sanitizing as to make Volk’s suspicion of
Green the following day unreasonable. We conclude that
Volk had a “particularized and objective” basis for suspecting
that Green was engaged in criminal activity on April 5,

, so extending the traffic stop to
facilitate a dog sniff was permissible, 

.
        For the reasons explained above, we will affirm the
decision of the District Court.




                              27