PUBLISHED

                      UNITED STATES COURT OF APPEALS
                          FOR THE FOURTH CIRCUIT


                                      No. 17-4109


UNITED STATES OF AMERICA,

                    Plaintiff – Appellee,

             v.

RAYMOND IDEMUDIA AIGBEKAEN,

                    Defendant – Appellant.



Appeal from the United States District Court for the District of Maryland, at Baltimore.
James K. Bredar, Chief District Judge. (1:15-cr-00462-JKB-2)


Argued: May 8, 2019                                       Decided: November 21, 2019


Before MOTZ, WYNN, and RICHARDSON, Circuit Judges.


Affirmed by published opinion. Judge Motz wrote the majority opinion, in which Judge
Wynn joined. Judge Richardson wrote an opinion concurring in the judgment.


ARGUED: Michael Lawlor, BRENNAN, MCKENNA & LAWLOR, CHTD., Greenbelt,
Maryland, for Appellant. Matthew James Maddox, OFFICE OF THE UNITED STATES
ATTORNEY, Baltimore, Maryland, for Appellee. ON BRIEF: Robert K. Hur, United
States Attorney, Ayn B. Ducao, Assistant United States Attorney, OFFICE OF THE
UNITED STATES ATTORNEY, Baltimore, Maryland, for Appellee.
DIANA GRIBBON MOTZ, Circuit Judge:

       In April of 2015, a minor alerted law enforcement officers that Raymond Idemudia

Aigbekaen and another man had trafficked her for sex in three mid-Atlantic states. As part

of the investigation that followed, when Aigbekaen returned to the United States from

traveling abroad, the Government seized his MacBook Pro laptop, iPhone, and iPod at the

airport and conducted warrantless forensic searches of the data on all three devices. The

Government subsequently charged Aigbekaen with sex trafficking and related crimes, and

at the conclusion of a nine-day trial, the jury convicted him of these crimes.

       Aigbekaen appeals, arguing primarily that the warrantless forensic searches of his

digital devices violated the Fourth Amendment.         The Government counters that the

searches fell within the “border search” exception to the warrant requirement and that, in

any event, suppression is not appropriate. We agree with Aigbekaen that the border search

exception does not extend to the challenged searches, rendering them unconstitutional. But

we agree with the Government that the good-faith exception to the exclusionary rule bars

suppression. Accordingly, we affirm.



                                             I.

       On April 12, 2015, a sixteen-year-old girl (to whom we, like the parties, refer

pseudonymously as “L.”) called 911 from a Homewood Suites hotel in Bel Air, Maryland.

L. reported that she had run away from home and was looking for help. When an officer

arrived on the scene and spoke with L., she claimed not to remember with whom she had

traveled or where she had been. But after some equivocation, L. disclosed that two men,

                                             2
one named Marcell Greene and another of Nigerian ethnicity named “Raymond,” had

transported her around Maryland, Virginia, and Long Island, New York; had posted ads of

her on Backpage.com; and had trafficked her for sex. L. provided phone numbers for these

men and identified Greene and Raymond Aigbekaen in hotel surveillance footage. She

also recognized images of herself from online prostitution ads on Backpage.com.

Homewood Suites records showed that Aigbekaen had rented L.’s hotel room. Officers

searched the room and found used condoms. 1

       Local law enforcement officers then sent their complete case file to Homeland

Security Investigations (HSI), an investigative arm of the U.S. Department of Homeland

Security.   After receiving the case file, HSI subpoenaed Verizon Wireless and

Backpage.com; the companies’ responses confirmed that the phone number L. had

provided indeed belonged to Aigbekaen, and that this number was listed as a contact on

the Backpage.com prostitution ads. The Backpage.com ads were also linked to two Yahoo!

email addresses, each of which contained portions of Aigbekaen’s name. HSI further

uncovered rental car and hotel records that showed Aigbekaen had traveled to hotels in

Maryland, Virginia, and Long Island.




       1
          By the time of Aigbekaen’s trial, L. was able to testify more fully that she and two
other girls had fled a group home in Dix Hills, New York in January 2015 to live with a
man named Y.P., who trafficked them for sex. L. was able to escape Y.P. with Greene’s
sister, Jasmine. But Jasmine relocated L. to Greene’s home, where Greene and Jasmine
decided to continue trafficking her. Greene then contacted Aigbekaen, who joined the
scheme. Greene and Aigbekaen proceeded to transport L. around Maryland, Virginia, and
Long Island, where she had sex for pay with as many as five men each day. Greene and
Aigbekaen kept all of the proceeds.
                                              3
        HSI agents learned that Aigbekaen had left the country and was set to return through

John F. Kennedy International Airport. The agents asked U.S. Customs and Border

Protection officers to seize any electronic media devices in Aigbekaen’s possession at the

airport upon his return. On May 19, 2015, the officers honored this request and, without

warrants, seized Aigbekaen’s MacBook Pro laptop computer, iPhone, and iPod. The

officers transported the devices to Baltimore, where an HSI agent created and reviewed a

forensic image of each device. HSI did not return the devices to Aigbekaen until June 2,

2015.       The forensic search 2 of the laptop revealed temporary backups of Facebook

Messenger conversations between Aigbekaen and another user that apparently related to

sex trafficking.

        A few months after the warrantless forensic searches, the Government secured and

executed search warrants for the same MacBook Pro and iPhone, Aigbekaen’s Facebook

and Yahoo! accounts, his vehicle, five additional cell phones, his DNA, and Greene’s

residence. A magistrate judge also granted the Government’s application to procure cell

site location information (“CSLI”) under the Stored Communications Act (“SCA”) without

obtaining a warrant.




        2
          A “forensic search” is “a powerful tool” capable of not only viewing data that a
user has intentionally saved on a digital device, but also “unlocking password-protected
files, restoring deleted material, and retrieving images viewed on websites.” United States
v. Cotterman, 

, 957 (9th Cir. 2013). Unlike a “manual” search of a digital
device, a forensic search generally entails the connection of external equipment and/or the
use of specialized software. United States v. Kolsuz, 

, 146 & n.6 (4th Cir.
2018).
                                             4
       In the midst of these warrant and SCA applications, a grand jury indicted Greene

and Aigbekaen on six counts, all of which related to interstate sex trafficking of L. and

transportation of her for the purpose of prostitution. Prior to trial, Aigbekaen moved to

suppress various pieces of evidence, including (as relevant here) any evidence recovered

from the May 2015 warrantless forensic searches.

       Aigbekaen argued that the May 2015 forensic searches were unconstitutional

because they were conducted without warrants and did not fall within the border search

exception to the warrant requirement. Aigbekaen maintained that “there has to be a point

at which the nature of the government investigation is so separated and so divorced from

anything related to the border” that the exception becomes inapplicable. He explained that

the Government’s “general interest in enforcing [domestic] criminal laws” does not

constitute an interest justifying “border searches.” The Government responded that, at the

time of the forensic searches, it had reasonable suspicion both that Aigbekaen had

trafficked L. for sex domestically and that he “might be bringing contraband in the form of

child pornography into the country,” citing for the latter argument only an “allegation from

the manager of the hotel where the victim was recovered.”

       At the close of the suppression hearing, the district court dismissed the

Government’s child pornography argument as “a lot weaker” but held that under “the

traditional border search analysis,” “the circumstances of where the property was and

where the person was when the search occurred” “trump[ed]” any need to justify the

specific search. As a result, the court found that no warrants were required for the May

2015 searches. The court further reasoned that if any individualized suspicion was needed

                                             5
to justify the “intrusive” forensic searches of Aigbekaen’s devices, the Government met

this standard because HSI had “at least” reasonable suspicion, if not probable cause, that

the warrantless searches would reveal evidence of domestic sex trafficking. 3

       The court thus denied the suppression motion, and Aigbekaen proceeded to trial.

After considering testimony from over twenty witnesses, a jury found Aigbekaen guilty on

all six counts. Aigbekaen timely noted this appeal.



                                             II.

       Aigbekaen’s principal argument on appeal is that the May 2015 warrantless forensic

searches of his laptop, iPhone, and iPod violated the Fourth Amendment. Although the

Government contends (and we ultimately agree) that the good-faith exception to the

exclusionary rule requires affirmance in any event, “when a Fourth Amendment case

presents a novel question of law whose resolution is necessary to guide future action by

law enforcement officers and magistrates, there is sufficient reason for [a court] to decide

the violation issue before turning to the good-faith question.” United States v. Bosyk, 933




       3
        Prior to trial, Aigbekaen also moved to suppress the CSLI on the ground that the
Government’s procurement of it constituted a search and so required a warrant. He later
conceded, and the district court held, that then-controlling circuit precedent foreclosed his
claim. See United States v. Graham, 

, 424–25 (4th Cir. 2016) (en banc),
abrogated by Carpenter v. United States, 

, 2223 (2018). During the
pendency of this appeal, the Supreme Court vindicated Aigbekaen’s position. See
Carpenter, 138 S. Ct. at 2223. But as Aigbekaen acknowledges, binding circuit precedent
nevertheless precludes suppression of the CSLI because the Government obtained it in
good-faith reliance on a federal statutory scheme — namely, the SCA. United States v.
Chavez, 

, 608 (4th Cir. 2018).
                                             

, 332 n.10 (4th Cir. 2019) (alterations in original) (quoting Illinois v. Gates, 

, 264 (1983) (White, J., concurring)).

       We review the district court’s legal conclusions de novo and its factual findings for

clear error, considering the record evidence in the light most favorable to the Government.

Kolsuz, 890 F.3d at 141–42. Because the Government conducted the challenged searches

without warrants, it bears the burden of proving, by a preponderance of the evidence, that

an exception to the warrant requirement applies. United States v. Davis, 

, 262

(4th Cir. 2012).

                                             A.

       The Fourth Amendment requires that governmental searches and seizures be

reasonable. In most cases, this requires a warrant based on probable cause. See, e.g., Riley

v. California, 

, 382 (2014). 4 “In the absence of a warrant, a search is

reasonable only if it falls within a specific exception to the warrant requirement.” Riley,

573 U.S. at 382.

       One such exception applies at our nation’s borders, where the Supreme Court has

long recognized the federal Government’s substantial sovereign interests in “protect[ing]

. . . territorial integrity” and national security, United States v. Flores-Montano, 

         Aigbekaen maintains that Riley, which held the search incident to arrest exception
inapplicable to modern cell phones, similarly renders the border search exception
categorically inapplicable to modern cell phones and analogous digital devices. See id. at
403. However, we have held after Riley that law enforcement officers may conduct a
warrantless forensic search of a cell phone under the border search exception where the
officers possess sufficient individualized suspicion of transnational criminal activity. See
Kolsuz, 890 F.3d at 148. Accordingly, we must reject Aigbekaen’s interpretation of Riley.
                                             7
149, 153 (2004); blocking “the entry of unwanted persons and effects,” id. at 152;

“regulat[ing] the collection of duties,” United States v. Montoya de Hernandez, 

, 537 (1985); and “prevent[ing] the introduction of contraband,” id. These Government

concerns are “at [their] zenith” at the border, whereas an individual’s “expectation of

privacy is less at the border than it is in the interior.” Flores-Montano, 541 U.S. at 152,

154. Thus, “[a]t a border” or its “functional equivalent, like [an] international airport . . .

government agents may conduct routine searches and seizures of persons and property

without a warrant or any individualized suspicion.” Kolsuz, 890 F.3d at 137 (internal

quotation marks omitted).

       Although this “border search” exception to the warrant requirement is broad, it is

not boundless. Even when the exception applies, the Supreme Court has explained that

certain “highly intrusive searches” may qualify as “‘nonroutine’” and so require some level

of individualized suspicion. Flores-Montano, 541 U.S. at 152 (quoting Montoya de

Hernandez, 473 U.S. at 541 n.4). Just last year, we applied this principle in the context of

an intrusive forensic search of a cell phone at the border. Given the “unparalleled breadth

of private information” that such a search could reveal, we held that “a forensic search of

a digital phone must be treated as a nonroutine border search, requiring some form of

individualized suspicion” even if not a warrant. Kolsuz, 890 F.3d at 145–46. 5 If the border

exception applies to the May 2015 forensic searches of Aigbekaen’s devices, these searches




       5
        We declined to decide whether reasonable suspicion was sufficient to justify such
a search or whether, instead, probable cause was required. Id. at 148.
                                              8
(like the forensic searches in Kolsuz) were sufficiently intrusive to be “nonroutine” and so

required some level of individualized suspicion. Id. at 137.

       But this raises another question: Does the border exception even apply to the May

2015 forensic searches?      Phrased differently, of what must the Government have

individualized suspicion for the border search exception to apply? Again, precedent offers

a clear answer. As the Supreme Court and this court have repeatedly explained, “the scope

of a warrant exception should be defined by its justifications.” Id. at 143 (citing Riley, 573

U.S. at 385–91); accord, e.g., Arizona v. Gant, 

, 351 (2009) (“When the[]

justifications” underlying an exception to the warrant requirement “are absent, a

[warrantless] search . . . will be unreasonable . . . .”). That is to say, a warrant exception

will not excuse a warrantless search where applying the exception “would untether the rule

from the justifications underlying [it].” Riley, 573 U.S. at 386 (internal quotation marks

omitted).

       The same limitation applies to the border search exception. Indeed, neither the

Supreme Court nor this court has ever authorized a warrantless border search unrelated to

the sovereign interests underpinning the exception, let alone nonroutine, intrusive searches

like those at issue here. Rather, our decision in Kolsuz teaches that the Government may

not “invoke[] the border exception on behalf of its generalized interest in law enforcement

and combatting crime.” 890 F.3d at 143. This restriction makes particularly good sense

as applied to intrusive, nonroutine forensic searches of modern digital devices, which store

vast quantities of uniquely sensitive and intimate personal information, id. at 145 (citing

Riley, 573 U.S. at 393–97), yet cannot contain many forms of contraband, like drugs or

                                              9
firearms, the detection of which constitutes “the strongest historic rationale for the border-

search exception,” United States v. Molina-Isidoro, 

, 295 (5th Cir. 2018)

(Costa, J., concurring).

       Accordingly, as we explained in Kolsuz, 890 F.3d at 143, to conduct such an

intrusive and nonroutine search under the border search exception (that is, without a

warrant), the Government must have individualized suspicion of an offense that bears some

nexus to the border search exception’s purposes of protecting national security, collecting

duties, blocking the entry of unwanted persons, or disrupting efforts to export or import

contraband. See also United States v. Ramsey, 

, 620 (1977) (“The border-

search exception is grounded in the recognized right of the sovereign to control, subject to

substantive limitations imposed by the Constitution, who and what may enter the

country.”). If a nonroutine search becomes too “attenuated” from these historic rationales,

it “no longer [will] fall under” the exception.       Kolsuz, 890 F.3d at 143.       In such

circumstances, the search will be unconstitutional unless accompanied by a warrant or

justified under a different exception to the warrant requirement.

       Applying these principles to the facts at hand, we can only conclude that the

warrantless forensic searches of Aigbekaen’s devices in May of 2015 lacked the requisite

nexus to the recognized historic rationales justifying the border search exception. Of

course, when Aigbekaen landed at the airport with his MacBook Pro, iPhone, and iPod in

tow, HSI agents had not only reasonable suspicion but probable cause to suspect that he

had previously committed grave domestic crimes. But these suspicions were entirely

unmoored from the Government’s sovereign interests in protecting national security,

                                             10
collecting or regulating duties, blocking Aigbekaen’s own entry, or excluding contraband.

Thus, holding the border search exception applicable here, based simply on the

Government’s knowledge of domestic crimes, would “untether” that exception from its

well-established justifications. Riley, 573 U.S. at 386.

       Resisting this result, the Government asserts that Aigbekaen’s crime “clearly was

one that is the proper subject of a border search, because [sex trafficking] is a crime

‘commonly involving cross-border movements.’” Supp. Response Br. at 13 (quoting

United States v. Caballero, 

, 1017 n.7 (S.D. Cal. 2016)). Of course,

the general character of a crime may be relevant to an officer’s reasonable suspicion that it

involves a transnational component. But inherent in the notion of individualized suspicion

is some evidentiary basis for what a specific crime does involve in the individual case at

hand, not just what it “commonly involves” as a general matter. Here, the Government has

offered no reasonable basis to suspect that Aigbekaen’s domestic crimes had any such

transnational component.

       We also must reject the district court’s conclusion that a nonroutine, intrusive

search’s physical and temporal proximity to an international border “trumps everything”

under the Fourth Amendment. To be sure, the Supreme Court has stated that routine border

searches “are reasonable simply by virtue of the fact that they occur at the border.” Ramsey,

431 U.S. at 616. But in the context of “highly intrusive” nonroutine border searches,

Flores-Montano, 541 U.S. at 152, the Court has explicitly struck a “balance between the

interests of the Government and the privacy right of the individual,” Montoya de

Hernandez, 473 U.S. at 540; see also Riley, 573 U.S. at 385 (instructing courts to evaluate

                                             11
any exception to the warrant requirement by weighing individual privacy interests against

“legitimate governmental interests” (quoting Wyoming v. Houghton, 

, 300

(1999))). Consistent with this balancing, we clarified in Kolsuz that a nonroutine search’s

location is not dispositive of whether the border search exception applies; rather, it is the

search’s relation to the Government’s sovereign interests that is paramount. 890 F.3d at

142–43.

       Moreover, “the ultimate touchstone of the Fourth Amendment is reasonableness.”

Riley, 573 U.S. at 381 (internal quotation marks omitted). And on the facts of this case,

the reasonableness of requiring law enforcement to secure a warrant before conducting an

intrusive forensic search of a traveler’s digital device, solely to seek evidence of crimes

with no transnational component, is readily apparent. By the time Aigbekaen arrived at

the airport with his devices, and prior to any searches of those devices, HSI agents had

probable cause to believe that Aigbekaen’s laptop, at least, contained evidence of domestic

sex trafficking. Indeed, in August of 2015, HSI secured warrants to search both the

MacBook Pro and the iPhone, relying almost exclusively on evidence that was in agents’

possession before Aigbekaen arrived at the airport in May. Given the information in its

possession at the time, it is only reasonable to expect the Government to have procured

these warrants prior to the May searches. 6


       6
        Of course, if HSI agents were unable to timely secure such warrants and reasonably
feared that Aigbekaen would destroy the evidence in the meantime, the exigent
circumstances exception might apply. See Riley, 573 U.S. at 402 (noting that Fourth
Amendment “exigencies could include the need to prevent the imminent destruction of
evidence in individual cases”). But the Government does not even suggest that exigency
played any role here.
                                              12
       In contrast, it would be patently unreasonable to permit highly intrusive forensic

Government searches of travelers’ digital devices, without warrants, on bases unrelated to

the United States’s sovereign authority over its borders. To be clear, we do not question

the import of the Government’s general interest in combatting crime. But we cannot agree

that this interest categorically eclipses individuals’ privacy interests in the vast troves of

data contained on their digital devices when the suspected offenses have little or nothing

to do with the border.

       As the Supreme Court explained in Riley, “[m]odern cell phones, as a category,

implicate privacy concerns far beyond those implicated” by physical searches. Id. at 393.

This is so because cell phones and other modern digital devices feature “an element of

pervasiveness” that distinguishes them from physical records; these days, “it is the person

who is not carrying a cell phone, with all that it contains, who is the exception.” Id. at 395.

At the same time, these devices have “immense storage capacity,” as well as cloud storage

capabilities, which they use to collect “in one place many distinct types of information . . .

that reveal much more in combination than any isolated record.” Id. at 393–94, 397. These

include unusually sensitive data regarding one’s relationships, personal interests and

preferences, prior internet searches, location history, and much more. Id. at 395–96. To

adopt the Government’s position, we would need to hold that it could conduct a warrantless

forensic search of any traveler’s cell phone — uncovering all of this data, including

“password-protected” and “deleted material[s],” Cotterman, 709 F.3d at 957 — on

suspicion that the phone may contain evidence of any prior domestic crime.



                                              13
       Because Aigbekaen does not challenge any routine border searches, we need not

decide whether or how the interests that underpin the border search exception constrain, in

practice, the Government’s broad and historic authority to conduct suspicionless searches

of individuals and their effects at the border. Ramsey, 431 U.S. at 616. Similarly, we need

not determine what quantum of individualized suspicion, if any, beyond the familiar

reasonable-suspicion standard is needed to justify a warrantless forensic search of a device

at the border.

       We simply apply the teaching of Kolsuz: where a search at the border is so intrusive

as to require some level of individualized suspicion, the object of that suspicion must bear

some nexus to the purposes of the border search exception in order for the exception to

apply. Because no such nexus existed here, the warrantless, nonroutine forensic searches

violated the Fourth Amendment.

                                            B.

       The Government briefly presses two secondary arguments in an attempt to establish

that the May 2015 searches were constitutional. Neither is persuasive.

       First, the Government devotes four sentences of briefing to a claim that at the time

of the warrantless searches, it “had a concern” that Aigbekaen’s devices “might” contain

not only evidence of past crimes, but also child pornography. Because of this “concern,”

the Government maintains, the warrantless forensic searches featured both individualized

suspicion and the requisite nexus to a dominant interest underpinning the border search

exception: preventing contraband from entering the country.



                                            14
       Like the district court, we do not find this claim persuasive. Even assuming that a

warrantless forensic search of a digital device at the border could be justified by reasonable

suspicion, 7 we can discern no “particularized and objective basis” in the record for agents

to reasonably suspect that Aigbekaen possessed child pornography on his devices.

Montoya de Hernandez, 473 U.S. at 541 (internal quotation marks omitted).                The

Government’s stated “concern” is based on a local police officer’s brief testimony, during

the suppression hearing, that a hotel manager received a tip from an unnamed employee

that the employee had “overheard one of the gentlem[e]n staying in the room [saying], you

know, let’s hurry up and get this video done.” Suppr. Hr’g Tr., ECF No. 193, at 217–19.

During cross-examination, the officer was asked if the hotel manager “ever g[a]ve [him]

any other indication as to why that [unnamed] employee thought that there was some type

of movie making or video making going on,” to which he replied, “No.” Id. at 217. At

trial, although the hotel manager recounted in detail the events surrounding L.’s 911 call,

he could no longer recall hearing any such statement from an employee or relating it to law

enforcement. 9/23/16 Trial Tr., ECF No. 259, at 69–70, 76. This isolated, vague, and

third-hand allegation does not rise to the level of reasonable suspicion. 8




       7
         See Kolsuz, 890 F.3d at 148 (declining to determine “whether more than reasonable
suspicion is required for a search of this nature”).
       8
         Notably, although the Government asserted at oral argument before us that it had
probable cause (not just reasonable suspicion) to suspect Aigbekaen’s devices contained
child pornography, not one of HSI’s numerous warrant affidavits and CSLI applications
included any such allegations. Nor did the HSI agent who testified at the suppression
hearing mention any suspicion that Aigbekaen’s devices contained child pornography.
                                             15
       Second, the Government suggests that the requisite nexus to the purposes of the

border search exception was present because Aigbekaen was a “criminal[]” seeking to enter

the United States and carried the “instrumentalities” of his domestic crime (that is, his

digital devices) into the country with him. Again, we must disagree. If the border search

exception is to retain any distinction from the Government’s “generalized interest in law

enforcement and combatting crime,” Kolsuz, 890 F.3d at 143, it cannot be invoked to

sanction invasive and nonroutine warrantless searches of all suspected domestic

“criminals,” nor the suspected “instrumentalities” of their domestic crimes. Importantly,

the Government does not contend (save for its unavailing child pornography claim) that

these “instrumentalities” were contraband.

       Because the Government lacked sufficient individualized suspicion of criminal

activity with any nexus to the sovereign interests underlying the border search exception,

its warrantless forensic searches of Aigbekaen’s devices violated the Fourth Amendment.



                                             III.

       In the alternative, the Government argues that any constitutional infirmity in the

May 2015 searches does not justify reversal for several independent reasons. We turn now

to these contentions.

                                             A.

       In its brief, the Government maintains that any dispute over these searches is moot

because no tainted evidence was admitted at trial. However, the record belies this assertion.

At the very least, HSI’s affidavit in support of the warrant to search Aigbekaen’s Facebook

                                             16
account relied on conversations and screen shots uncovered during the May 2015

searches. 9 And the Government introduced the Facebook warrant returns at trial.

       At oral argument before us, the Government did not dispute these facts. Instead, it

sought to refashion its mootness claim, asserting in its place that the August 2015 warrant-

backed searches of Aigbekaen’s devices constituted an “independent source” that cured

any taint from the prior warrantless searches. The record evidence, however, does not

support application of the independent-source doctrine. Under that doctrine, evidence

“initially discovered during, or as a consequence of, an unlawful search, but later obtained

independently from activities untainted by the initial illegality” may be admitted at trial.

Murray v. United States, 

, 537 (1988). But later activities, like the August

2015 searches, do not qualify as independent sources if “the agents’ decision to seek the

warrant[s] was prompted by what they had seen during the initial [searches].” Id. at 542.

As the Government conceded at oral argument, the district court did not make any factual

findings on this point. Mindful of the Supreme Court’s admonition that “it is the function

of the District Court rather than the Court of Appeals to determine the facts,” id. at 543, we

cannot assume in the first instance that the August 2015 warrants were not prompted by

the May 2015 warrantless searches.

                                             B.

       The Government next contends that the good-faith exception to the exclusionary

rule bars suppression of any evidence tainted by any constitutional defect in the May 2015


       9
        The district court later opined that the probable cause underlying this warrant, even
with these allegations, was “a little thin.”
                                             17
searches. Aigbekaen counters that the lack of a nexus renders the good-faith exception

inapplicable. On this point, we must agree with the Government.

       The evidentiary fruits of Fourth Amendment violations are generally inadmissible

at trial. See Wong Sun v. United States, 

, 484–85 (1963). But the fruits of “a

search conducted in reasonable reliance on binding precedent [are] not subject to the

exclusionary rule,” as that rule is designed “to deter future Fourth Amendment violations.”

Davis v. United States, 

, 236–37, 241 (2011) (emphasis added).

       In this case, the HSI agents who searched Aigbekaen’s devices in May of 2015

reasonably relied on an “established and uniform body of precedent allowing warrantless

border searches of digital devices.” Kolsuz, 890 F.3d at 148. Although it has long been

understood that the scope of a warrant exception should be tailored to the purposes

underlying that exception, no court had yet applied that principle to require a warrant “for

any border search, no matter how nonroutine or invasive.” Id. at 147; see also Molina-

Isidoro, 884 F.3d at 294 (Costa, J., concurring) (noting that “no reported federal decision

has required a warrant for any border search”). Only in 2018 did this court recognize that

“a search initiated at the border could become so attenuated from the rationale for the

border search exception that it no longer would fall under that exception” and so require a

warrant. Kolsuz, 890 F.3d at 143. And only today have we applied that principle to hold

unconstitutional such an attenuated, warrantless, nonroutine forensic search at the border.

       Tellingly, Aigbekaen offers almost no argument against application of the good-

faith exception, save for a question-begging allegation that the Government “attempt[ed]

to exploit an exception to the Fourth Amendment warrant requirement.” He may well be

                                            18
correct that even prior to Kolsuz, “the better practice” would have been for the Government

to get a warrant in the first place. But good faith does not mandate best practices. Given

the uniform body of precedent that permitted warrantless searches at the border in May of

2015, we cannot help but conclude that the good-faith exception applies here. 10



                                              IV.

       For the foregoing reasons, the judgment of the district court is

                                                                                  AFFIRMED.




       10
          Aigbekaen also argues, in supplemental briefing, that the multi-week seizures of
his digital devices constituted an unreasonable interference with his possessory interests.
See United States v. Pratt, 

, 271–73 (4th Cir. 2019). However, Aigbekaen
opted neither to press this claim before the district court nor to raise it in his opening brief
to this court. In fact, when the district court asked Aigbekaen’s counsel whether he
intended to develop a factual record regarding the reasonableness of the seizures, his
counsel chose not to “request[] any further information” on the issue. We decline to
address this forfeited claim. In his pro se brief and supplemental briefs, Aigbekaen also
raises a host of additional challenges to his conviction and sentence. Although “an
appellant who is represented by counsel has no right to file pro se briefs or raise additional
substantive issues in an appeal,” United States v. Cohen, 

, 682 (4th Cir. 2018),
we have examined Aigbekaen’s contentions and find no reversible error.
                                              19
RICHARDSON, Circuit Judge, concurring in the judgment:

       For the first time in this Circuit, the Majority holds a border search unlawful by

applying a “nexus” requirement tethered to narrowly defined purposes that supposedly

underlie the border-search doctrine: national security, blocking the entry of persons, and

disrupting the trafficking of contraband. And, although my good colleagues agree that law

enforcement reasonably suspected a foreign national of interstate sex trafficking, this

reasonable suspicion is not enough for them. Because interstate sex trafficking—as

“distinguished” from international sex trafficking—lacks the Majority’s requisite nexus to

the perceived purposes of the border-search doctrine, the Majority holds the search of a sex

trafficker’s cell phone at the border violates the Fourth Amendment.

       In my view, the Majority errs in adopting a “nexus” test that is in deep tension with

Supreme Court precedent. And even assuming the “nexus” test were proper, I would find

it satisfied here.

       In the end, the Majority affirms Aigbekaen’s conviction based on the good-faith

exception to the exclusionary rule. And I agree with that judgment. But I respectfully

disagree with the decision to declare this border search unlawful.

                                             I.

       The Fourth Amendment prohibits “unreasonable searches and seizures.” U.S.

CONST. amend. IV. And as the Supreme Court has explained, “reasonableness” is the

“ultimate touchstone of the Fourth Amendment.” Riley v. California, 

, 381

(2014) (quoting Brigham City v. Stuart, 

, 403 (2006)). In determining what

is reasonable, courts look to longstanding traditions with an eye towards determining “that


                                            20
degree of privacy against government that existed when the Fourth Amendment was

adopted.” United States v. Jones, 

, 406 (2012) (quoting Kyllo v. United States,

, 34 (2001)); see also Riley, 573 U.S. at 382 (looking to the historical bases for

a search incident to arrest).

       One such tradition, the “border-search doctrine,” gives government agents at

international borders broad discretion to search people and their effects. United States v.

Ramsey, 

, 616–17 (1977). The border-search doctrine has “a history as old as

the Fourth Amendment itself,” id. at 619, and rests on the principle “that the United States,

as sovereign, has the inherent authority to protect, and a paramount interest in protecting,

its territorial integrity,” United States v. Flores-Montano, 

, 153 (2004); cf.

United States v. Curtiss-Wright Exp. Corp., 

, 318 (1936) (describing territorial

integrity as inherent to sovereignty). Thus, the government’s “interest in preventing the

entry of unwanted persons and effects is at its zenith at the international border.” Flores-

Montano, 541 U.S. at 152. And travelers understand that they subject themselves and their

property to some form of search by crossing international boundaries. As a result, “the

expectation of privacy is less at the border than it is in the interior.” Id. at 154.

       Supreme Court jurisprudence purports to reflect the border-search doctrine’s

historical scope. See Ramsey, 431 U.S. at 616–19; see also Boyd v. United States, 

, 623–24 (1886). But in the three decades since Ramsey, more historical work has been

done to understand the Fourth Amendment. See, e.g., WILLIAM J. CUDDIHY, The Fourth

Amendment: Origins and Original Meaning 602–1791 (2009). And in recent years, some

work has begun to better understand the border-search doctrine itself—analyzing the


                                               21
backdrop English common-law doctrine, the historical understanding of sovereign

prerogatives under international law, the drafting and ratification history of the Fourth

Amendment (and relevant state analogues), and statutes enacted around the time the Bill

of Rights was ratified (such as the Collection Acts of 1789 and 1790). See, e.g., Note, The

Border Search Muddle, 132 HARV. L. REV. 2278, 2287–97 (2019).

       Based on this more recent historical work, one might ask whether Ramsey’s

historical analysis would change (or perhaps be confirmed) if we were to revisit the

relevant historical sources (including those left aside by Ramsey). But this case is neither

the time nor the place to do so. We are an inferior court (to say nothing of the lack of

briefing focused on this historical inquiry and a somewhat limited academic literature

focused on the border-search doctrine). As an inferior court, we take the Supreme Court’s

precedents as we find them.

       And the Supreme Court has repeatedly upheld border agents’ broad discretion to

conduct searches in sweeping terms, requiring particularized suspicion only for especially

intrusive searches.   The distinction between “routine” searches and highly intrusive

“nonroutine” searches provides the analytical linchpin for determining whether

particularized suspicion is required at the border. An agent may undertake routinely

intrusive border searches of international travelers—such as patting them down for

weapons and rummaging through their luggage—with no articulable suspicion. Flores-

Montano, 541 U.S. at 152.

       Highly intrusive searches at the border that are deemed nonroutine are different. For

this limited category, the government must articulate reasonable suspicion. United States


                                            22
v. Montoya de Hernandez, 

, 542 (1985). 1 In Montoya de Hernandez, border

agents suspected a woman, who had arrived on an international flight, of swallowing

balloons containing illegal drugs. Id. at 534−35. Agents strip searched the woman and

detained her for over sixteen hours so that they could inspect the results of a bowel

movement. Id. at 535. Eventually, a federal magistrate authorized a rectal examination,

which uncovered a balloon filled with cocaine (the first of eighty-eight ultimately

revealed). Id. Even on these facts, the Supreme Court held that only reasonable suspicion

was needed to detain the woman. Id. at 541.

       The Supreme Court has suggested that only three highly intrusive situations may

qualify as nonroutine: (1) “highly intrusive searches of the person,” (2) searches of

property that are “destructive,” and (3) searches carried out in a “particularly offensive”

manner.    Flores-Montano, 541 U.S. at 152–56, 154 n.2; see also United States v.

Cotterman, 

, 973 (9th Cir. 2013) (en banc) (Callahan, J., concurring in part,

dissenting in part, and concurring in the judgment).

       In making this distinction based on the intrusiveness of a search, the Court considers

whether the subject of a search is a person or property. Despite hinting at the possibility

that a “destructive” search of property might amount to a nonroutine search, see Flores-

Montano, 541 U.S. at 152–56, 154 n.2, the Supreme Court has never actually held that any

search of property—as opposed to persons—was “nonroutine.” See, e.g., United States v.


       1
        The potential that particularized suspicion might be required for more intrusive
searches had been left open by older precedents. See Ramsey, 431 U.S. at 618 n.13 (not
“decid[ing] whether, and under what circumstances, a border search might be deemed
‘unreasonable’ because of the particularly offensive manner in which it is carried out”).

                                             23
Touset, 

, 1234 (11th Cir. 2018) (“Property and persons are different.”). And

the Court has set a high bar for when a property search might ever rise to that level. In

Flores-Montano, the Court held that customs officers conducted only a “routine” search

when they stopped and dissembled a vehicle to remove and inspect its gas tank. 541 U.S.

at 155–56. In so holding, the Court instructed that, where border searches of property were

involved, only “destructive” or otherwise “particularly offensive” searches of that property

would be so intrusive as to require any particularized suspicion. See id. at 154 n.2. The

Supreme Court also chastised lower courts for being too quick to undermine the simplicity

of the border-search doctrine for property with “[c]omplex balancing tests to determine

what is a ‘routine’ search,” explaining that such tests “have no place in border searches of

vehicles.” Id. at 152.

       Despite that guidance on searches of property at the border, in United States v.

Kolsuz, 

 (4th Cir. 2018), we held that a detailed “forensic” search—as opposed

to a “manual” search—of an international traveler’s electronic devices at the border was

“nonroutine” and thus required particularized suspicion. See id. at 144 (relying, in part, on

Riley v. California, 

 (2014)). That holding may be controversial. See, e.g.,

Touset, 890 F.3d at 1233–36. But whatever one thinks of creating a constitutional

distinction between “forensic” and “manual” searches of property, it is the law of our

circuit. And so I assume that some degree of suspicion was required for the forensic search

of Aigbekaen’s electronic devices.

       Kolsuz also addressed, and rejected, an argument that the search in that case had an

inadequate “nexus” to the purposes of the border-search doctrine. We first observed that,


                                             24
“[a]s a general rule, the scope of a warrant exception should be defined by its

justifications.” Kolsuz, 890 F.3d at 143 (citing Riley, 573 U.S. at 384–92). We then noted,

in general terms, the possibility that a search “could become so attenuated from the

rationale for the border search exception that it would no longer fall under that exception.”

Kolsuz, 890 F.3d at 143 (emphasis added). We held that the search before us in that case

did not fail “on any account of a ‘nexus’ requirement” because the crime being investigated

had a “transnational” nature. Id. That is, Kolsuz held that suspicion of transnational crime

was sufficient to satisfy any potential “nexus” requirement.

       Kolsuz did not hold that such suspicion was necessary for a border search. Nor did

Kolsuz explain the rationale for the border-search doctrine or otherwise explore the bounds

of what constitutes an adequate transnational “nexus.” And so the Majority overstates the

case when it claims that Kolsuz held that “where a search at the border is so intrusive as to

require some level of individualized suspicion, the object of that suspicion must bear some

nexus to the purposes of the border search exception in order for the exception to apply.”

Majority Op. at 14. Kolsuz merely noted the possible existence of a “nexus” requirement

and, assuming it existed, concluded that it was satisfied.

                                             II.

       In this case, the Majority goes beyond Kolsuz by imposing this transnational

“nexus” requirement to hold a border search unlawful for the first time in our circuit.

                                             A.

       Before evaluating the Majority’s “nexus” requirement, I briefly note what I

understand it to be, and not to be. The Majority opinion does not cast doubt on non-


                                             25
invasive searches (like going through someone’s luggage) that happen every day at the

border. If such “routine” searches could be challenged as having an inadequate “nexus” to

the border, the border-search doctrine would be eviscerated. Thankfully, the Majority does

not go there (although it does not rule out the possibility of going there in the future, and it

may be challenging to maintain a principled reason for not doing so). 2

       Instead, the Majority’s “nexus” requirement comes into play (for now) only for the

more intrusive “nonroutine” searches that already require objective, particularized

suspicion. It seeks to regulate what kind of particularized suspicion is required. In the

Majority’s view, the grounds for suspicion must dovetail with the ultimate purposes of the




       2
         The Ninth Circuit has gone there. United States v. Cano, 

, 1016 (9th
Cir. 2019) (holding that “border searches are limited in scope to searches for contraband
and do not encompass searches for evidence of past or future border-related crimes”). In
that case, the court held that agents could conduct a “manual” search of a phone without
any suspicion but that the search exceeded the permissible scope of a border search when
agents recorded phone numbers and messages. Id. at 1019. The Ninth Circuit reasoned
that recording numbers and messages went beyond what was reasonably necessary to
search for contraband. Id. I find the Ninth Circuit’s reasoning on that point hard to accept,
both for the reasons I explain below and under the plain-view doctrine: surely, if officers
have discovered information during a lawful search, recording that information does not
render the search unlawful.

                                              26
border-search doctrine. 3       Having reason to believe that the search will uncover

contraband—for example, that the person’s cell phone contains child pornography—

necessarily corresponds to the Majority’s purposes of the border-search doctrine. The

Majority is also willing to permit searches for evidence of “transnational” criminal activity.

But when agents seek evidence of domestic crimes, my colleagues decide they need

probable cause and a warrant.

                                                      B.

         This “nexus” requirement is inconsistent with the Supreme Court’s border-search

cases.       Those cases consistently describe the government’s powers at the border in

sweeping terms:

                 Time and again, we have stated that “searches made at the
                 border, pursuant to the longstanding right of the sovereign to
                 protect itself by stopping and examining persons and property
                 crossing into this country, are reasonable simply by virtue of
                 the fact that they occur at the border.” . . . It is axiomatic that
                 the United States, as sovereign, has the inherent authority to
                 protect, and a paramount interest in protecting, its territorial
                 integrity.

Flores-Montano, 541 U.S. at 152–53 (quoting Ramsey, 531 U.S. at 616). The Supreme

Court has limited the border-search doctrine only when the intrusiveness of the search

makes it unreasonable without particularized suspicion—not based on the government’s


         3
         The precise type of “reasonable suspicion” required to establish a nexus has
divided courts. Compare United States v. Cano, 934 F.3d at 1020 (narrower: reasonable
suspicion that searched item contains contraband), with Majority Op. at 9–11 (broader:
reasonable suspicion of prohibited transnational activity). Of course, in the context of
border searches involving child pornography stored in cell phones, the suspicion of
contraband (child pornography) and of ongoing prohibited transnational activity
(smuggling of child pornography) will overlap.

                                                 27
interests or a “nexus” between these interests and the specific search conducted. See id.

The Court has authorized no further exceptions to the near-absolute description of the

doctrine in Flores-Montano and Ramsey. In fact, it has cautioned lower courts against

creating them. Id.

       The Majority’s innovation is to limit the border-search doctrine based not on the

intrusiveness of the search, but on the nature of the government’s interests at stake. Not

only is there no support for this innovation in the Supreme Court’s border-search cases, but

this also ignores the Court’s admonitions to interpret the doctrine broadly and avoid

creating new limitations.

       Now there is an argument that the border-search doctrine should be limited in this

way—or perhaps even more narrowly. Some jurists have taken the view that the border-

search doctrine is concerned solely with detection of contraband. See, e.g., Cano, 934 F.3d

at 1016−19; United States v. Vergara, 

, 1317 (11th Cir. 2018) (Pryor, J.,

dissenting). And this narrow reading has some historical support. After all, the Supreme

Court has mainly grounded the border-search doctrine in founding-era statutes that

authorized warrantless customs inspections. Ramsey, 431 U.S. at 616–17 (citing Act of

July 31, 1789, ch. 5, § 24, 1 Stat. 29, 43); see also Act of Aug. 4, 1790, ch. 35, § 31, 1 Stat.

145, 164–65 (permitting revenue collectors to board and search vessels in coastal waters

without suspicion); id. at §§ 47–48, 1 Stat. at 169–70 (permitting revenue collectors to open

containers on vessels “on suspicion of fraud” without a warrant).

       On the other hand, there are reasons to conclude that this “contraband-only” view

might be too narrow given the interests of the United States, as sovereign, at its territorial


                                              28
borders. As we observed in Kolsuz, the government has a broader national-security interest

at the border that goes beyond the immediate search for contraband. 890 F.3d at 143. So

we noted that the doctrine should encompass searches for evidence of “ongoing efforts to

export contraband illegally, through searches initiated at the border,” id. at 143−44, not just

“direct interception of contraband,” id. at 143. Thus construed, the purposes of the border-

search doctrine overlap to some degree with general law enforcement.

       And the Supreme Court has described the border-search doctrine as being concerned

with regulating the movement not only of goods, but also of people. Carroll v. United

States, 

, 154 (1925). It is “‘without doubt’ that the power to exclude aliens

‘can be effectuated by routine inspections and searches of individuals or conveyances

seeking to cross our borders.’” Ramsey, 431 U.S. at 619 (quoting Almeida-Sanchez v.

United States, 

, 272 (1973)); see also United States v. Oriakhi, 

,

1296 (4th Cir. 1995) (“From the sovereign’s power to protect itself is derived its power to

exclude harmful influences, including undesirable aliens, from the sovereign’s territory.”).

And the Supreme Court has articulated the federal government’s control over migration—

and the nation’s borders—as near-plenary. See, e.g., Ramsey, 431 U.S. at 619; see also

U.S. ex rel. Knauff v. Shaughnessy, 

, 542 (1950).

       But no matter how we, as lower-court judges, might wish to shape the doctrine, we

are not free to rewrite the Supreme Court’s case law based on our own ideas. And that law

is sweeping in its deference to the authority of the government to conduct searches at the

border.




                                              29
       Without support in the Court’s border-search cases, the Majority bases its “nexus”

requirement on the Court’s analysis of the search-incident-to-arrest exception in Riley v.

California, 

 (2014). Like the Kolsuz panel, my colleagues read Riley to say

that, “[a]s a general rule, the scope of a warrant exception should be defined by its

justifications.” Kolsuz, 890 F.3d at 143. But transplanting Riley’s “general rule” into the

specific context of border searches to support the “nexus” requirement raises at least two

problems.

       First, Riley said nothing about border searches; it concerned the far different context

of searches incident to arrest. We cannot, as lower-court judges, strain to insert the

Supreme Court’s reasoning from one line of cases into another where it does not fit.

Particularly where two areas of case law point in different directions, we must follow the

cases that are most on point. 4 And as I have explained, the Court has never held that the

border-search doctrine should be “defined by its justifications.” Id. at 143. To the contrary,

it has articulated the doctrine in sweeping terms and told us to apply it accordingly.




       4
         There are, moreover, important differences between a search incident to arrest and
a border search. These differences undermine any reliance on Riley’s search-incident-to-
arrest analysis to support the “nexus” requirement in the border-search context. For one,
the two doctrines have different justifications. The border-search doctrine, unlike the
search-incident-to-arrest doctrine, implicates the sovereign’s paramount interest in
protecting its territorial integrity—suggesting a far broader scope than the narrower
rationales justifying the search-incident-to-arrest doctrine. And unlike searches incident to
arrest, border searches are based in part on implied consent. Just as airline passengers
understand that having their bodies scanned and their bags x-rayed is part of the price of
admission to modern airports, so travelers at international crossings have long understood
that they are subjecting themselves to search at the border.

                                             30
       And second, Riley itself does not support the Majority’s approach. Riley made clear

that we should be looking categorically at the type of search—not the suspicion motivating

the search. Riley considered whether the search-incident-to-arrest doctrine, which permits

warrantless and suspicionless searches of an arrestee’s person and immediate surroundings,

should apply to cell-phone searches. In addressing that issue, the Court noted that it had

limited the scope of searches falling within this doctrine. For example, the “extensive

warrantless search of [an arrestee’s] home” cannot be justified as an incident to arrest. 573

U.S. at 383 (citing Chimel v. California, 

, 763, 768 (1969)). This doctrine

also does not justify the search of a car once the arrestee has been secured or otherwise

brought beyond reach of the vehicle’s passenger compartment. Id. at 374 (citing Arizona

v. Gant, 

 (2009)). The Riley Court determined that, for similar reasons, the

“particular category of effects” before it (i.e., cell phones) fell outside the search-incident-

to-arrest doctrine. Id. at 386. In doing so, the Court insisted that the availability of the

exception must turn categorically on the type of search. It expressly rejected the prospect

of “case-by-case adjudication” resting on “the probability in a particular arrest situation

that weapons or evidence would in fact be found.” Id. at 384 (quoting United States v.

Robinson, 

, 235 (1973)).

       The Majority takes the very approach that Riley rejected, making the scope of the

border-search doctrine turn not just on the type of the search as a categorical matter but

also on a case-by-case analysis of the probability of finding contraband or evidence of a

“transnational” crime in the context of a specific search. If the Majority wants to rely on

Riley’s search-incident-to-arrest analysis, it should take the bitter with the sweet.


                                              31
       Thus, even if Riley has relevance for border searches, it teaches us to adopt a simpler

test, one unconcerned with the type of misconduct under investigation. Rather than look

at the type of governmental interest, the Supreme Court has already instructed us to look

at the type of search to determine what, if any, requirements should apply. Montoya de

Hernandez has given us a two-step analysis based on the type of border search: if the

search is routinely intrusive, then no suspicion is required; if the search is highly intrusive

and thus nonroutine, then some particularized suspicion is required. See United States v.

Oriakhi, 

, 1297 (4th Cir. 1995) (citing Montoya de Hernandez, 

,

541 (1985)). 5 Instead of looking to the degree of intrusion, the Majority’s “nexus”

approach focuses on the purpose of the search. This approach fails to faithfully follow

either the Supreme Court’s border-search cases or Riley. I, therefore, respectfully disagree

with the Majority’s decision to hold the search unlawful on that basis.

                                              C.

       Despite my reservations, the Majority has made its “nexus” requirement the law of

this circuit. Having created it, how should it be applied? While apparently leaving the

details to another day, the Majority does require that officers have some basis to believe

that the border search will uncover (1) contraband or (2) evidence of a “transnational”



       5
         Perhaps there should be a third category for the most intrusive searches, like body-
cavity searches, where more than reasonable suspicion is required. But the Supreme Court
has not yet adopted one in its border-search cases (admittedly without ruling one out, see
Montoya de Hernandez, 473 U.S. at 541 n.4). And in evaluating its intrusiveness, a cell-
phone search surely cannot require more than the reasonable suspicion needed to justify
the “long, uncomfortable, indeed, humiliating” detention in Montoya de Hernandez. Id. at
544.

                                              32
crime. Applying that test here, the Majority concludes that the agents’ suspicion at the

time of the search failed to meet this requirement because, while Aigbekaen was suspected

of being an interstate sex trafficker, he was not suspected of being an international sex

trafficker. In my view, the Majority’s application of its “nexus” requirement is too narrow.

       Consider the evidence that the agents had against Aigbekaen when they conducted

the search. On April 12, 2015, a sixteen-year-old girl called 911 from a hotel in Bel Air,

Maryland. J.A. 53. She told police that “Raymond” and another man had taken her from

New York to Maryland and Virginia, where they had sold her to over one hundred men for

sex over the course of a few weeks.          She also explained that the men had used

Backpage.com to advertise her services.           Based on her statement and additional

information (a review of Backpage.com postings and hotel records), police identified both

men. J.A. 67. They learned that “Raymond” meant Aigbekaen, a Nigerian national, who

had paid for the room. J.A. 66. A search of the hotel room revealed used condoms. J.A.

272. Police also spoke to a manager at the hotel, who overheard the two men referring to

a “movie” they were making. J.A. 270. Officers learned that Aigbekaen had left the

country but would be returning to the United States at JFK International Airport. J.A. 107.

They alerted border agents, who stopped Aigbekaen at customs on May 19, 2015, and

searched his electronic devices. J.A. 108.

       As the Majority agrees, officers had probable cause to believe that Aigbekaen was

engaged in interstate sex trafficking of underage girls. Police had the underage victim’s

statement. They also found evidence that Aigbekaen rented a hotel room used for sex with

the girl. And there was evidence that Aigbekaen had used the internet to commit his crimes


                                             33
by posting advertisements on Backpage.com. This meant, of course, that there was

probable cause to believe that searching Aigbekaen’s electronic devices would turn up

relevant evidence. And it would beggar belief to claim that Aigbekaen’s crimes were

purely historical. Police knew that Aigbekaen had recently sold one underage victim to

over one hundred men over a short time. The reasonable inference was that his criminal

activity was professional and ongoing.

       These facts also supported reasonable suspicion that Aigbekaen’s interstate crimes

had an international component. Police knew he was a foreign national who trafficked

underage girls across state lines for profit and that, while engaged in that business, he

traveled abroad. There was at least some reason to suspect that Aigbekaen’s foreign travels

were not purely personal, but professional as well.

       Police also reasonably suspected that Aigbekaen was a foreign national traveling

from abroad into the United States with the intent to continue his criminal activity. Cf.

United States v. Oriakhi, 

, 1296 (4th Cir. 1995) (“From the sovereign’s power

to protect itself is derived its power to exclude harmful influences, including undesirable

aliens, from the sovereign’s territory.”).

       And despite the Majority’s suggestion, we may view the facts particular to

Aigbekaen against the background understanding that many sex crimes have a

transnational component. The trafficking of women across international lines is well

documented. So is the phenomenon of international “sex tourism.” These suspicions about

international misconduct may not have risen to the level of probable cause. But they did




                                             34
rise to the level of reasonable suspicion, which is all we should require to find an adequate

“nexus.” 6

       There were also reasonable grounds to suspect that Aigbekaen’s electronic devices

contained child pornography—a type of contraband. Aigbekaen had posted suggestive

photos of the underage victim on Backpage.com. While these photos apparently did not

constitute child pornography, there was reason to suspect that Aigbekaen might also have

more explicit pictures of his victims. (Indeed, given how widely used cell-phone cameras

are, one might reasonably guess that very few sex traffickers of underage girls do not have

child pornography on their phones.) But there was even more direct evidence: the hotel

manager had overheard Aigbekaen and his co-conspirator referring to a “movie” they were

making. Child pornography is contraband, and reasonable suspicion at the border that

someone’s electronic devices possess child pornography should be enough for a forensic

search under any theory.

       The Majority strains to conclude that there was no such reasonable suspicion. But

the Majority simply misapplies the law, in effect applying a standard tantamount to

probable cause (or perhaps something even more demanding). Reasonable suspicion

merely means, under “the totality of the circumstances,” there is “a particularized and

objective basis for suspecting legal wrongdoing.” United States v. Bernard, 

,

805 (4th Cir. 2019) (quoting United States v. Vaughan, 

, 710 (4th Cir. 2012)).


       6
        The Majority holds that the government lacked reasonable suspicion, leaving open
what level of suspicion is generally necessary for this type of search. I would require no
more than reasonable suspicion—assuming, of course, that some type of suspicion of a
nexus-related activity should be required in the first place.

                                             35
For example, if police see someone “driving erratically,” they have reasonable suspicion

that he might be “impaired or fatigued”—despite having no direct evidence. Id. In the

classic case, officers had “reasonable suspicion” that a group of men were planning to rob

a convenience store based on a combination of otherwise “innocent” acts, such as standing

around, walking back and forth, talking to each other, and looking at the store repeatedly.

Terry v. Ohio, 

, 22–23 (1968). Here, there was a particularized and objective

basis for suspecting that Aigbekaen—a foreign national who trafficked underage girls for

sex across state lines, took photos of them, and was overheard discussing a “movie” with

his accomplice—was engaged in illegal conduct during his foreign travels, was entering

the country to keep engaging in ongoing and future criminal schemes, and had explicit

photos of underage girls on his phone.

       In sum, there was reasonable suspicion that Aigbekaen had contraband and that his

interstate crimes also had the “transnational” component the Majority would require. That

should be more than enough.

                                            ***

       The scope of the border-search doctrine raises difficult questions. But in my view,

the Majority’s “nexus” requirement does not faithfully follow the Supreme Court’s case

law. In any event, this requirement is satisfied here, making it a particularly troubling case

to reach beyond good faith to find the search unlawful.




                                             36