United States v. Miguel Cano ( 2019 )


Menu:
  •                       FOR PUBLICATION
    UNITED STATES COURT OF APPEALS
    FOR THE NINTH CIRCUIT
    UNITED STATES OF AMERICA,                    No. 17-50151
    Plaintiff-Appellee,
    D.C. No.
    v.                      3:16-cr-01770-BTM-1
    MIGUEL ANGEL CANO,
    Defendant-Appellant.                    OPINION
    Appeal from the United States District Court
    for the Southern District of California
    Barry Ted Moskowitz, District Judge, Presiding
    Argued and Submitted April 10, 2019
    Pasadena, California
    Filed August 16, 2019
    Before: Susan P. Graber and Jay S. Bybee, Circuit Judges,
    and M. Douglas Harpool,* District Judge.
    Opinion by Judge Bybee
    *
    The Honorable M. Douglas Harpool, United States District Judge
    for the Western District of Missouri, sitting by designation
    2                    UNITED STATES V. CANO
    SUMMARY**
    Criminal Law
    The panel reversed the district court’s order denying the
    defendant’s motion to suppress evidence obtained from
    warrantless searches of his cell phone by Customs and Border
    Protection officials, and vacated his conviction for importing
    cocaine.
    Applying United States v. Cotterman, 
    709 F.3d 952
     (9th
    Cir. 2013) (en banc), the panel held that manual cell phone
    searches may be conducted by border officials without
    reasonable suspicion but that forensic cell phone searches
    require reasonable suspicion. The panel clarified Cotterman
    by holding that “reasonable suspicion” in this context means
    that officials must reasonably suspect that the cell phone
    contains digital contraband. The panel further concluded that
    cell phone searches at the border, whether manual or forensic,
    must be limited in scope to whether the phone contains digital
    contraband; and that a broader search for evidence of a crime
    cannot be justified by the purposes of the border search
    exception to the Fourth Amendment warrant requirement.
    The panel held that to the extent that a Border Patrol
    agent’s search of the defendant’s phone – which included the
    recording of phone numbers and text messages for further
    processing – went beyond a verification that the phone lacked
    digital contraband, the search exceeded the proper scope of a
    border search and was unreasonable as a border search under
    **
    This summary constitutes no part of the opinion of the court. It has
    been prepared by court staff for the convenience of the reader.
    UNITED STATES V. CANO                       3
    the Fourth Amendment. The panel held that although the
    agents had reason to suspect the defendant’s phone would
    contain evidence leading to additional drugs, the record does
    not give rise to an objectively reasonable suspicion that the
    digital data in the phone contained contraband, and the border
    search exception therefore did not authorize the agents to
    conduct a warrantless forensic search of the defendant’s
    phone. The panel held that the good faith exception to the
    exclusionary rule does not apply because the border officials
    did not rely on binding appellate precedent specifically
    authorizing the cell phone searches at issue here.
    Rejecting the defendant’s contention that the government
    violated his rights under Brady v, Maryland, 
    373 U.S. 83
    (1963), and Fed. R. Crim. P. 16, by failing to turn over certain
    information he requested from the FBI and DEA in pursuit of
    this third-party defense, the panel found no evidence that the
    prosecution had knowledge or possession of evidence
    showing that the defendant’s cousin or his cousin’s gang were
    involved in drug trafficking at the Mexico-California border,
    and held that the prosecutor should not be held to have
    “access” to any information that an agency not involved in
    the investigation or prosecution of the case refuses to turn
    over.
    4                 UNITED STATES V. CANO
    COUNSEL
    Harini P. Raghupathi (argued), Federal Defenders of San
    Diego, Inc., San Diego, California, for Defendant-Appellant.
    Mark R. Rehe (argued), Assistant United States Attorney;
    Helen H. Hong, Assistant United States Attorney, Chief,
    Appellate Section, Criminal Division; Adam L. Braverman,
    United States Attorney; United States Attorney’s Office, San
    Diego, California; for Plaintiff-Appellee.
    Sophia Cope and Adam Schwartz, Electronic Frontier
    Foundation, San Francisco, California, for Amicus Curiae
    Electronic Frontier Foundation.
    OPINION
    BYBEE, Circuit Judge:
    Defendant-Appellant Miguel Cano was arrested for
    carrying cocaine as he attempted to cross into the United
    States from Mexico at the San Ysidro Port of Entry.
    Following his arrest, a Customs and Border Protection
    official seized Cano’s cell phone and searched it, first
    manually and then using software that accesses all text
    messages, contacts, call logs, media, and application data.
    When Cano moved to suppress the evidence obtained from
    the warrantless searches of his cell phone, the district court
    held that the searches were valid under the border search
    exception to the Fourth Amendment’s warrant requirement.
    Applying United States v. Cotterman, 
    709 F.3d 952
     (9th
    Cir. 2013) (en banc), we conclude that manual cell phone
    UNITED STATES V. CANO                     5
    searches may be conducted by border officials without
    reasonable suspicion but that forensic cell phone searches
    require reasonable suspicion. We clarify Cotterman by
    holding that “reasonable suspicion” in this context means that
    officials must reasonably suspect that the cell phone contains
    digital contraband. We further conclude that cell phone
    searches at the border, whether manual or forensic, must be
    limited in scope to a search for digital contraband. In this
    case, the officials violated the Fourth Amendment when their
    warrantless searches exceeded the permissible scope of a
    border search. Accordingly, we hold that most of the
    evidence from the searches of Cano’s cell phone should have
    been suppressed. We also conclude that Cano’s Brady claims
    are unpersuasive. Because we vacate Cano’s conviction, we
    do not reach his claim of prosecutorial misconduct.
    We reverse the district court’s order denying Cano’s
    motion to suppress and vacate Cano’s conviction.
    I. THE BACKGROUND
    A. The Facts
    Defendant-Appellant Miguel Cano worked in the flooring
    and carpet installation trade and lived with his wife and
    children in the Mission Hills community north of Los
    Angeles. In the summer of 2016, however, Cano moved from
    Los Angeles to Tijuana, Mexico, where he stayed with his
    cousin Jose Medina. While staying with Medina, Cano
    crossed the border into the United States six times, sometimes
    remaining in the United States for less than thirty minutes.
    On two of those trips, Cano was referred to secondary
    inspection, but no contraband was found.
    6                 UNITED STATES V. CANO
    On July 25, 2016, Cano arrived at the San Ysidro Port of
    Entry from Tijuana. In primary inspection, Cano stated that
    “he was living in Mexico, working in San Diego, but going to
    LA on that day.” Pursuant to a random Customs and Border
    Protection (CBP) computer referral, Cano was referred to
    secondary inspection, where a narcotic-detecting dog alerted
    to the vehicle’s spare tire. A CBP official removed the spare
    tire from the undercarriage of the truck and discovered 14
    vacuum-sealed packages inside, containing 14.03 kilograms
    (30.93 pounds) of cocaine.
    Cano was arrested, and a CBP official administratively
    seized his cell phone. The CBP officials called Homeland
    Security Investigations (HSI), which dispatched Agents
    Petonak and Medrano to investigate. After arriving, Agent
    Petonak “briefly” and manually reviewed Cano’s cell phone,
    noticing a “lengthy call log” but no text messages. Agent
    Petonak later stated that the purpose of this manual search
    was “two-pronged”: “to find some brief investigative leads in
    the current case,” and “to see if there’s evidence of other
    things coming across the border.”
    Agent Petonak proceeded to question Cano, who waived
    his Miranda rights and agreed to talk. During that interview,
    Cano denied any knowledge of the cocaine. Cano stated that
    he had moved to Tijuana to look for work in nearby San
    Diego, because work was slow in Los Angeles. He also said
    he had crossed the border every day for the previous three
    weeks looking for work. He told Agent Petonak that he was
    headed to a carpet store in Chula Vista that day to seek work.
    When pressed, Cano was not able to provide the name or
    address of the store, claiming that he intended to look it up on
    Google after crossing the border. Cano also explained that he
    did not have his flooring tools with him in his pickup truck so
    UNITED STATES V. CANO                      7
    as to avoid problems with border crossings; Cano intended to
    drive to Los Angeles to retrieve his tools if he located work
    in San Diego.
    During the interrogation, Agent Petonak specifically
    asked Cano about the lack of text messages on his cell phone.
    Cano responded that his cousin had advised him to delete his
    text messages “just in case” he got pulled over in Mexico and
    police were to check his cell phone. Cano stated that he
    erased his messages to avoid “any problems” with the
    Mexican police.
    While Agent Petonak questioned Cano, Agent Medrano
    conducted a second manual search of the cell phone. Agent
    Medrano browsed the call log and wrote down some of the
    phone numbers on a piece of paper. He also noticed two
    messages that arrived after Cano had reached the border, and
    he took a photograph of the messages. The first message
    stated, “Good morning,” and the second message stated,
    “Primo, are you coming to the house?” Agent Medrano gave
    all of this information—the recorded list of calls and the
    photograph—to Agent Petonak.
    Finally, Agent Medrano conducted a “logical download”
    of the phone using Cellebrite software. A Cellebrite search
    enables the user to access text messages, contacts, call logs,
    media, and application data on a cell phone and to select
    which types of data to download. It does not, however, allow
    the user to access data stored within third-party applications.
    Agent Medrano typically does not select the option to
    download photographs.
    After Agent Petonak interviewed Cano, he reviewed the
    results of the Cellebrite download of Cano’s phone by Agent
    8                    UNITED STATES V. CANO
    Medrano. The Cellebrite results revealed that Cano had sent
    no text messages, and it listed all the calls made by Cano.
    Agent Petonak later concluded that none of the phone
    numbers in the call log corresponded to carpeting stores in
    San Diego.
    B. The Proceedings
    Cano was indicted for importing cocaine. Before trial,
    Cano moved to suppress any evidence obtained from Agents
    Petonak and Medrano’s warrantless searches of his cell phone
    at the border. The district court denied Cano’s motion, ruling
    that the manual searches and the Cellebrite search of Cano’s
    phone were valid border searches. During trial, the
    government introduced evidence that resulted from the
    manual searches of the phone and from Agent Medrano’s
    Cellebrite download of the phone.1
    In preparation for trial, Cano indicated his intent to
    present a third-party culpability defense claiming that his
    cousin, Jose Medina, was responsible for placing the drugs in
    Cano’s spare tire without Cano’s knowledge. Cano proffered
    evidence that Medina had a key to Cano’s car and had driven
    it shortly before Cano’s attempted border crossing, that
    1
    Some—but not all—of the evidence was available through
    alternative channels. For example, the government introduced a call log,
    unchallenged by Cano, that the government received from Cano’s phone
    company. Similarly, the government later obtained a warrant to search the
    phone, and an agent conducted further searches. Because the government
    introduced at trial much evidence pre-dating those events, and because the
    government has not argued that any Fourth Amendment error was
    harmless, those later events do not affect our Fourth Amendment analysis
    of the warrantless searches. United States v. Rodriguez, 
    880 F.3d 1151
    ,
    1163 (9th Cir. 2018)
    UNITED STATES V. CANO                      9
    Medina had a criminal record including a conviction for
    cocaine possession, that Medina was a member of a Chicago-
    based gang called the Latin Kings, and that the Latin Kings
    sold cocaine within the United States and were involved with
    a cartel that trafficked drugs across the border.
    Following Cano’s implication of Medina, the government
    contacted Medina and promised him immunity and
    immigration papers in exchange for his cooperation. Medina
    initially denied being involved with drugs, but later contacted
    the government on his own and offered to help them with the
    “biggest RICO case” and “drug seizures of 20 to 25
    kilograms at a time.” All of this information was made
    available to Cano.
    As part of his defense, Cano sought additional discovery
    from HSI, the Federal Bureau of Investigation (FBI), and the
    Drug Enforcement Agency (DEA) regarding: (1) records
    linking Medina to drug sales, distribution, or trafficking; and
    (2) records linking the Latin Kings to drug trafficking from
    Mexico to Southern California. The government opposed
    Cano’s discovery motion, arguing that the evidence was not
    material under Federal Rule of Criminal Procedure
    16(a)(1)(E)(i) and that discovery should be limited to HSI, as
    neither the DEA nor the FBI had participated in the
    investigation of Cano. The district court originally overruled
    both objections, finding the evidence material under Rule 16
    and exculpatory under Brady v. Maryland, 
    373 U.S. 83
    (1963). The court also reasoned that, because HSI could
    inquire of the DEA and FBI if it sought inculpatory evidence,
    HSI had access to the files and was required to provide any
    exculpatory evidence held by the DEA or FBI.
    10                   UNITED STATES V. CANO
    In response to the court’s discovery order, HSI produced
    Medina’s immigration file and his Bureau of Prisons record.
    Agent Petonak also searched for Medina’s name in two
    different police clearinghouses, but neither returned any hits.2
    Both Agent Petonak and the United States Attorney’s Office
    (USAO) subsequently requested information showing a link
    between the Latin Kings and drug trafficking from Mexico
    from the legal counsel of both the FBI and DEA. Both
    agencies denied the requests without providing any
    explanation or any indication as to whether the requested
    information existed.
    Following these attempts, the government moved for the
    district court to reconsider its discovery order and excuse it
    from discovery relating to files held by the FBI and DEA.
    The district court granted the motion to reconsider, finding
    that the prosecutor did not have access to the evidence when
    he was “rebuffed” by agencies over which he had no control.
    The case proceeded to trial and Cano presented his third-
    party culpability defense. The first trial resulted in a hung
    jury and a mistrial. On retrial, Cano again relied on his third-
    party culpability defense. The second trial resulted in Cano’s
    conviction. This appeal followed, in which Cano raises three
    issues: (1) whether the warrantless searches of his cell phone
    violated the Fourth Amendment and whether the resulting
    evidence should be suppressed; (2) whether the government’s
    non-disclosure of materials that may have been held by the
    DEA and FBI violated his right to due process under Brady
    2
    A police clearinghouse works for the purpose of “deconfliction” by
    notifying an agency if another agency has an investigation pending against
    the same person or item. The DEA and FBI participate in the two
    clearinghouses searched by Agent Petonak.
    UNITED STATES V. CANO                         11
    and Federal Rule of Criminal Procedure 16; and (3) whether
    the government raised an improper propensity inference in its
    closing argument. We address Cano’s first two arguments in
    turn. Because we conclude that the district court erred in
    denying Cano’s motion to suppress, we vacate Cano’s
    conviction and do not reach his claim of prosecutorial
    misconduct.
    II. THE WARRANTLESS SEARCH OF CANO’S
    CELL PHONE
    The Fourth Amendment protects “[t]he right of the people
    to be secure in their persons, houses, papers, and effects,
    against unreasonable searches and seizures.” U.S. Const.
    amend. IV.3 Ordinarily, before conducting a search, police
    must obtain a warrant issued by a judicial officer based “upon
    probable cause, supported by Oath or affirmation, and
    particularly describing the place to be searched, and the
    persons or things to be seized.” 
    Id.
     Warrants are generally
    required “unless ‘the exigencies of the situation’ make the
    needs of law enforcement so compelling that the warrantless
    search is objectively reasonable under the Fourth
    Amendment.” Mincey v. Arizona, 
    437 U.S. 385
    , 393–94
    (1978) (citation omitted). Consequently, “searches conducted
    outside the judicial process, without prior approval by judge
    or magistrate, are per se unreasonable under the Fourth
    Amendment—subject only to a few specifically established
    and well-delineated exceptions.” Katz v. United States, 
    389 U.S. 347
    , 357 (1967) (footnote omitted). Such “specifically
    established and well-delineated exceptions” include exigent
    3
    We review de novo “the district court’s determination that [a]
    warrantless search . . . was a valid border search.” United States v.
    Cardona, 
    769 F.2d 625
    , 628 (9th Cir. 1985).
    12                UNITED STATES V. CANO
    circumstances, searches incident to arrest, vehicle searches,
    and border searches. See Arizona v. Gant, 
    556 U.S. 332
    , 343
    (2009) (vehicle searches); Brigham City v. Stuart, 
    547 U.S. 398
    , 403 (2006) (exigent circumstances; listing other
    exceptions, including warrantless entry to fight a fire, to
    prevent the imminent destruction of evidence, or in “hot
    pursuit” of a fleeing suspect); United States v. Ramsey, 
    431 U.S. 606
    , 616 (1977) (border searches); Weeks v. United
    States, 
    232 U.S. 383
    , 392 (1914) (searches incident to arrest),
    overruled in part on other grounds by Mapp v. Ohio, 
    367 U.S. 643
     (1961).
    Exceptions to the warrant requirement are subject to two
    important constraints. First, any search conducted under an
    exception must be within the scope of the exception. Second,
    some searches, even when conducted within the scope of the
    exception, are so intrusive that they require additional
    justification, up to and including probable cause and a
    warrant.
    The first constraint is illustrated by the Supreme Court’s
    decision in Riley v. California, 
    573 U.S. 373
     (2014), a case
    involving the search incident to arrest exception. In Riley, the
    Court addressed “whether the police may, without a warrant,
    search digital information on a cell phone seized from an
    individual who has been arrested”; in other words, whether
    cell phones fell within the scope of the search incident to
    arrest exception. Id. at 378. The Court began by recognizing
    the increasing role in our lives of “minicomputers that also
    happen to have the capacity to be used as a telephone”;
    “[m]odern cell phones, as a category, implicate privacy
    concerns far beyond those implicated by the search of a
    cigarette pack, a wallet, or a purse.”            Id. at 393.
    Acknowledging that “it has been well accepted that [a search
    UNITED STATES V. CANO                      13
    incident to lawful arrest] constitutes an exception to the
    warrant requirement,” id. at 382, the Court pointed out that
    such searches serve two purposes: (1) to secure “the officer’s
    safety” and (2) to “prevent . . . concealment or destruction [of
    evidence],” id. at 383 (citation omitted). The Court then
    considered whether a cell phone search qualified as a search
    incident to arrest by considering “whether application of the
    search incident to arrest doctrine to [cell phones] would
    ‘untether the rule from the justifications underlying the . . .
    exception.’” Id. at 386 (quoting Gant, 
    556 U.S. at 343
    ).
    The Court concluded that neither purpose for the search
    incident to arrest exception justified the search of a cell
    phone. The Court rejected the government’s argument that
    searching a cell phone incident to arrest would “help ensure
    officer safety in . . . indirect ways, for example by alerting
    officers that confederates of the arrestee are headed to the
    scene.” 
    Id. at 387
    . The Court reasoned that the government’s
    position “would . . . represent a broadening” of the
    exception’s foundational concern that “an arrestee himself
    might grab a weapon and use it against an officer.” 
    Id.
     at
    387–88. The Court observed that “once law enforcement
    officers have secured a cell phone, there is no longer any risk
    that the arrestee himself will be able to delete incriminating
    data from the phone,” 
    id. at 388
    , and police have means to
    ensure that data cannot be wiped from the phone remotely,
    
    id. at 390
    . The Court concluded “not that the information on
    a cell phone is immune from search; [but rather] that a
    warrant is generally required before such a search, even when
    a cell phone is seized incident to arrest.” 
    Id. at 401
    .
    The second constraint on warrantless searches is
    illustrated by the Court’s decision in United States v.
    Montoya de Hernandez, 
    473 U.S. 531
     (1985). Montoya was
    14                UNITED STATES V. CANO
    stopped at Los Angeles International Airport and referred to
    secondary inspection. 
    Id. at 533
    . She had arrived from
    Bogota and was carrying $5,000 in cash. 
    Id.
     She had no
    credit cards and no hotel reservations. 
    Id.
     at 533–34.
    Because border officials suspected that Montoya may have
    swallowed cocaine-filled balloons, Montoya was held in the
    customs office and, after a magistrate judge issued an order,
    taken to a hospital for a rectal examination. 
    Id.
     at 534–35.
    Over the next four days, she passed 88 balloons containing
    cocaine. 
    Id. at 536
    . Montoya argued that the search she was
    subjected to, though a border search, was so intrusive that it
    could not be conducted without a high level of particularized
    suspicion. 
    Id.
     at 536–37, 540. The Court balanced her
    privacy interests against the interests of the government at the
    border and concluded that, while routine searches may be
    conducted at the border without any showing of suspicion, a
    more intrusive, nonroutine search must be supported by
    “reasonable suspicion.” 
    Id.
     at 537–41; see also United States
    v. Flores-Montano, 
    541 U.S. 149
    , 152 (2004) (suggesting that
    nonroutine searches are limited to “highly intrusive searches
    of the person” involving “dignity and privacy interests”).
    Cano recognizes that he was subject to search at the
    border, but Cano and amicus Electronic Frontier Foundation
    (“EFF”) raise two categorical challenges and one as-applied
    challenge to the searches conducted here. First, EFF argues
    that any warrantless search of a cell phone falls outside the
    scope of the border search exception. Second, EFF argues
    that even if the search is within the scope of the border search
    exception, a warrantless cell phone search is so intrusive that
    it requires probable cause. We address these categorical
    challenges in Part II.A. Third, Cano asserts that, even if cell
    phones are generally subject to search at the border, the
    manual and forensic searches of his cell phone exceeded the
    UNITED STATES V. CANO                    15
    “well delineated” scope of the border search. We address this
    as-applied question in Part II.B. Finally, the government
    argues that even if the border search exceeded the limits of
    the Fourth Amendment, the search was conducted in good
    faith, and the evidence is admissible. We consider the good
    faith exception in Part II.C.
    A. Border Searches and Cell Phones
    “[B]order searches constitute a ‘historically recognized
    exception to the Fourth Amendment’s general principle that
    a warrant be obtained.’” Cotterman, 709 F.3d at 957 (quoting
    Ramsey, 
    431 U.S. at 621
    ). Indeed, border searches typically
    do not require any particularized suspicion, so long as they
    are “routine inspections and searches of individuals or
    conveyances seeking to cross our borders.” Almeida-Sanchez
    v. United States, 
    413 U.S. 266
    , 272 (1973); see United States
    v. Seljan, 
    547 F.3d 993
    , 999 (9th Cir. 2008) (en banc). Such
    searches are “reasonable simply by virtue of the fact they
    occur at the border.” Ramsey, 
    431 U.S. at 616
    . The
    exception is “rooted in ‘the long-standing right of the
    sovereign to protect itself by stopping and examining persons
    and property crossing into this country,’” Cotterman, 709
    F.3d at 960 (quoting Ramsey, 
    431 U.S. at 616
    ), to “prevent[]
    the entry of unwanted persons and effects,” 
    id.
     (quoting
    Flores-Montano, 
    541 U.S. at 152
    ).
    The sovereign’s right to conduct suspicionless searches at
    the border “does not mean, however, that at the border
    ‘anything goes.’” 
    Id.
     (quoting Seljan, 
    547 F.3d at 1000
    ).
    Rather, the border search exception is a “narrow exception”
    that is limited in two important ways. 
    Id.
     (citation omitted).
    First, “[t]he authorizing statute limits the persons who may
    legally conduct a ‘border search’ to ‘persons authorized to
    16                    UNITED STATES V. CANO
    board or search vessels.’” United States v. Soto-Soto, 
    598 F.2d 545
    , 549 (9th Cir. 1979) (citing 
    19 U.S.C. § 482
    ).4 This
    includes customs and immigration officials, but not general
    law enforcement officers such as FBI agents. Id.; see United
    States v. Diamond, 
    471 F.2d 771
    , 773 (9th Cir. 1973) (stating
    that “customs agents are not general guardians of the public
    peace”). Second, a border search must be conducted “in
    enforcement of customs laws.” Soto-Soto, 
    598 F.2d at 549
    .
    A border search must be conducted to “enforce importation
    laws,” and not for “general law enforcement purposes.” 
    Id.
    4
    Section 482 now reads in relevant part:
    Any of the officers or persons authorized to board
    or search vessels may stop, search, and examine . . . any
    vehicle, beast, or person, on which or whom he or they
    shall suspect there is merchandise which is subject to
    duty, or shall have been introduced into the United
    States in any manner contrary to law . . . . [and may]
    seize and secure the same for trial.
    
    19 U.S.C. § 482
    (a); see 
    id.
     § 1467 (“[T]he appropriate customs officer for
    [a] port or place of arrival may . . . enforce, cause inspection, examination,
    and search to be made of the persons, baggage, and merchandise
    discharged or unladen from [an arriving] vessel . . . .”); id. § 1496 (“The
    appropriate customs officer may cause an examination to be made of the
    baggage of any persons arriving in the United States in order to ascertain
    what articles are contained therein and whether subject to duty, free of
    duty, or prohibited . . . .”); id. § 1582 (“[A]ll persons coming into the
    United States from foreign countries shall be liable to detention and search
    by authorized officers or agents . . . .”).
    The Court has described § 482 as granting the executive “plenary
    authority to conduct routine searches and seizures at the border, without
    probable cause or a warrant.” Montoya de Hernandez, 
    473 U.S. at 537
    .
    We have held that the “outer limits of authority delegated by [§ 482 are]
    available only in border searches.” Corngold v. United States, 
    367 F.2d 1
    , 3 (9th Cir. 1966) (en banc).
    UNITED STATES V. CANO                       17
    A general search cannot be “justif[ied] . . . on the mere basis
    that it occurred at the border.” 
    Id.
     (affirming the suppression
    of evidence where an FBI agent stopped and searched the
    vehicle of an alien to determine whether the car had been
    stolen).
    1. Cell Phone Data as Contraband
    As we discussed briefly above, the Supreme Court has
    identified two principal purposes behind warrantless border
    searches: First, to identify “[t]ravellers . . . entitled to come
    in” and, second, to verify their “belongings as effects which
    may be lawfully brought in.” Carroll v. United States, 
    267 U.S. 132
    , 154 (1925); see Ramsey, 
    431 U.S. at 620
     (“The
    border-search exception is grounded in the recognized right
    of the sovereign to control . . . who and what may enter the
    country.”).
    EFF argues that applying the border search exception to
    a cell phone’s data would “untether” the exception from the
    purposes underlying it. EFF contends that a border search
    encompasses only a search for illegal persons and physical
    contraband located on the body of the applicant for
    admission or among his effects. Because digital data on a cell
    phone cannot conceal objects such as drugs, guns, or
    smuggled persons, EFF asserts that digital cell phone
    searches are always beyond the scope of the border search
    exception.
    We agree with EFF that the purpose of the border search
    is to interdict contraband, but we disagree with its premise
    that cell phones cannot contain contraband. Although cell
    18                   UNITED STATES V. CANO
    phone data cannot hide physical objects,5 the data can contain
    digital contraband. The best example is child pornography.
    See United States v. Molina-Isidoro, 
    884 F.3d 287
    , 295 n.3
    (5th Cir. 2018) (Costa, J., specially concurring) (“One type of
    contraband that can be stored within the data of a cell
    phone . . . is child pornography.”). And because cell phones
    may ultimately be released into the interior, even if the owner
    has been detained, the United States has a strong interest in
    preventing the entry of such material. See, e.g., United States
    v. Vergara, 
    884 F.3d 1309
    , 1311 (11th Cir.) (describing how
    agents returned one of the defendant’s phones to a family
    member after defendant had been arrested for possessing
    child pornography on his other two phones), cert. denied, 
    139 S. Ct. 70
     (2018). We find no basis for the proposition that the
    border search exception is limited to searching for physical
    contraband. At the very least, a cell phone that has photos
    stored on it is the equivalent of photographs, magazines, and
    books.6 See Riley, 573 U.S. at 394; Cotterman, 709 F.3d at
    964. The contents may be digital when they are on the phone,
    but the physicality of the phone itself and the possibility that
    5
    No one contests that a border official could, consistent with the
    Fourth Amendment, examine the physical body of a cell phone to see if
    the phone itself is contraband—because, for example, it is a pirated copy
    of a patented U.S. phone—or if the phone itself presents a physical threat
    to officers. See Riley, 573 U.S. at 387 (“Law enforcement officers remain
    free to examine the physical aspects of a phone to ensure that it will not
    be used as a weapon—say, to determine whether there is a razor blade
    hidden between the phone and its case.”). The dispute here concerns only
    whether border officials may search the digital data contained within the
    phone.
    6
    We need not address here questions surrounding the use of “cloud
    computing,” where the phone gives access to, but does not contain in its
    own memory, digital data stored in the cloud. See Riley, 573 U.S. at
    397–98; Cotterman, 709 F.3d at 965 & n.12.
    UNITED STATES V. CANO                            19
    the phone’s contents can be printed or shared electronically
    gives border officials sufficient reason to inspect it at the
    border. We conclude that cell phones—including the phones’
    data—are subject to search at the border.
    2. Forensic Cell Phone Searches as an Intrusive Search
    The second question we must address in response to
    amicus EFF is whether forensic searches of a cell phone are
    so intrusive that they require reasonable suspicion or even
    probable cause. We answered this question in our en banc
    decision in Cotterman, but with respect to laptop computers.7
    Cotterman, 709 F.3d at 962–68. Cotterman was a United
    States citizen returning to the United States from Mexico. Id.
    at 957. When he reached the port of entry, border officials
    noted that Cotterman had various convictions for sexual
    conduct with children. Id. Concerned that Cotterman might
    be involved in child sex tourism, officials conducted a brief
    search of his laptop computers and digital cameras and noted
    that the laptops had password-protected files. Id. at 958. The
    officials detained the computers for several days in order to
    run a comprehensive forensic search of the hard drive, which
    revealed hundreds of images of child pornography. Id. at
    958–59. For us, “the legitimacy of the initial search of
    Cotterman’s electronic devices at the border [was] not in
    doubt,” id. at 960, “[t]he difficult question . . . [was] the
    reasonableness, without a warrant, of the forensic
    7
    Although Cotterman referred to “electronic devices” generally, see
    709 F.3d at 962–68, our holding was limited to the “examination of
    Cotterman’s computer,” id. at 968, and did not address cell phones. We
    mentioned cell phones only once—in the first paragraph of the
    introduction describing the modern “digital world.” Id. at 956.
    20                UNITED STATES V. CANO
    examination that comprehensively analyzed the hard drive of
    the computer,” id. at 961.
    We acknowledged the “substantial personal privacy
    interests” in “[e]lectronic devices . . . capable of storing
    warehouses full of information.” Id. at 964. At the same
    time, we recognized “the important security concerns that
    prevail at the border” and the legitimacy of “[t]he effort to
    interdict child pornography.” Id. at 966. We held that a
    routine, manual search of files on a laptop computer—“a
    quick look and unintrusive search”—is reasonable “even
    without particularized suspicion,” but that officials must
    “possess a particularized and objective basis for suspecting
    the person stopped of criminal activity” to engage in a
    forensic examination, which is “essentially a computer strip
    search.” Id. at 960–61, 966, 967 (citation omitted). We
    concluded that reasonable suspicion was “a modest, workable
    standard that is already applied in the extended border search,
    Terry stop, and other contexts.” Id. at 966; see id. at 968
    (defining reasonable suspicion as “a particularized and
    objective basis for suspecting the particular person stopped of
    criminal activity” (quoting United States v. Cortez, 
    449 U.S. 411
    , 417–18 (1981))).
    We think that Cotterman’s reasoning applies equally to
    cell phones. In large measure, we anticipated the Supreme
    Court’s reasoning in Riley, 573 U.S. at 393–97, when we
    recognized in Cotterman that digital devices “contain the
    most intimate details of our lives” and “the uniquely sensitive
    nature of data on electronic devices carries with it a
    significant expectation of privacy,” Cotterman, 709 F.3d at
    965–66; see Riley, 573 U.S. at 385, 393 (describing cell
    phones as “a pervasive and insistent part of daily life” that,
    “as a category, implicate privacy concerns far beyond those
    UNITED STATES V. CANO                               21
    implicated by the search of a cigarette pack, a wallet, or a
    purse”). The Court’s view of cell phones in Riley so closely
    resembles our own analysis of laptop computers in Cotterman
    that we find no basis to distinguish a forensic cell phone
    search from a forensic laptop search.8
    Nor do we believe that Riley renders the Cotterman
    standard insufficiently protective. Riley, of course, held that
    “a warrant is generally required” before searching a cell
    phone, “even when a cell phone is seized incident to arrest.”
    573 U.S. at 401. But here we deal with the border search
    exception—not the search incident to arrest exception—and
    the difference in context is critical. In light of the
    government’s enhanced interest in protecting the “integrity of
    the border” and the individual’s decreased expectation of
    privacy, the Court has emphasized that “the Fourth
    Amendment’s balance of reasonableness is qualitatively
    different at the international border than in the interior” and
    is “struck much more favorably to the Government.”
    Montoya de Hernandez, 
    473 U.S. at
    538–40. As a result,
    post-Riley, no court has required more than reasonable
    suspicion to justify even an intrusive border search. See
    United States v. Wanjiku, 
    919 F.3d 472
    , 485 (7th Cir. 2019)
    (“[N]o circuit court, before or after Riley, has required more
    than reasonable suspicion for a border search of cell phones
    or electronically-stored data.”); Touset, 890 F.3d at 1234
    8
    We note that the Eleventh Circuit disagreed with Cotterman in
    United States v. Touset, 
    890 F.3d 1227
    , 1234 (11th Cir. 2018). The court
    held that no level of suspicion was required to conduct a forensic search
    of a cell phone. 
    Id.
     at 1234–35. Nevertheless, the Touset court held, in
    the alternative, that the forensic search of various electronic devices seized
    at the border were supported by reasonable suspicion. Id. at 1237. As
    with most cell phone search cases, in Touset border agents were looking
    for child pornography.
    22                UNITED STATES V. CANO
    (“Riley, which involved the search-incident-to-arrest
    exception, does not apply to searches at the border.”);
    Molina-Isidoro, 884 F.3d at 291 (“For border searches both
    routine and not, no case has required a warrant.”); id. at 293
    (“The bottom line is that only two of the many federal cases
    addressing border searches of electronic devices have ever
    required any level of suspicion. They both required only
    reasonable suspicion and that was for the more intrusive
    forensic search.”); see also Kolsuz, 
    890 F.3d 133
    , 137 (4th
    Cir. 2018) (concluding that a “forensic examination of
    Kolsuz’s phone must be considered a nonroutine border
    search, requiring some measure of individualized suspicion”
    but declining to decide whether the standard should be
    reasonable suspicion or probable cause).
    Accordingly, we hold that manual searches of cell phones
    at the border are reasonable without individualized suspicion,
    whereas the forensic examination of a cell phone requires a
    showing of reasonable suspicion. See Cotterman, 709 F.3d
    at 968.
    B. The Searches of Cano’s Cell Phone and the Scope of the
    Border Search Exception
    Having concluded that border officials may conduct
    suspicionless manual searches of cell phones, but must have
    reasonable suspicion before they conduct a forensic search,
    we still must address the core of Cano’s argument: whether
    the manual and forensic searches of his cell phone were not
    searches for digital contraband, but searches for evidence of
    a crime, and thus exceeded the proper scope of a border
    search.
    UNITED STATES V. CANO                             23
    1. The Border Exception and the Search for Contraband
    As a threshold matter, Cano argues that border searches
    are limited in both purpose and scope to searches for
    contraband.9 In response, the government argues that
    searches for evidence that would aid in prosecuting past and
    preventing future border-related crimes are tethered to the
    purpose of the border search exception—namely, interdicting
    foreign contraband—and thus fall within its scope.
    9
    Cano emphasizes that the officials who arrested him were looking
    for evidence of a crime, not contraband that could be seized at the border,
    and this renders the search unconstitutional. He points to Officers Petonak
    and Medrano, who searched Cano’s cell phone, and who testified that their
    searches had a dual purpose: “to find some brief investigative leads in the
    current case” and “to see if there[] [was] evidence of other things coming
    across the border.” Because the agents acknowledged that they sought
    evidence to use against Cano in building a criminal case, Cano argues that
    the court should treat the search as one conducted for “general law
    enforcement purposes” rather than a border search.
    Cano’s focus on the officials’ subjective motivations is misplaced,
    however. As the district court recognized, “courts have repeatedly held
    that the Fourth Amendment’s reasonableness analysis is ‘predominantly
    an objective inquiry.’” See Whren v. United States, 
    517 U.S. 806
    , 813
    (1996) (upholding a “pretextual” stop because “[s]ubjective intentions
    play no role in ordinary . . . Fourth Amendment analysis”). We have
    upheld border searches of persons seeking entry even when those searches
    were conducted “at the behest” of DEA agents seeking criminal evidence.
    See United States v. Schoor, 
    597 F.2d 1303
    , 1305–06 (9th Cir. 1979)
    (holding a border search reasonable where it was conducted “at the
    behest” of DEA agents and included a search for certain items of evidence
    in addition to a search for contraband). Thus, the mere fact that Officers
    Petonak and Medrano subjectively hoped to find “investigative leads”
    pertaining to the seized shipment of cocaine does not render their searches
    of Cano’s phone beyond the border search exception.
    24                UNITED STATES V. CANO
    This is a close question, but we think Cano has the better
    of the argument. There is a difference between a search for
    contraband and a search for evidence of border-related
    crimes, although the distinction may not be apparent.
    Cotterman helps us focus on the difference. There, border
    officials had been alerted that Cotterman had a criminal
    record of sex abuse of minors and might be involved in “child
    sex tourism.” Cotterman, 709 F.3d at 957. The officials
    seized his laptop and subjected it to searches for child
    pornography, which they found. In Cotterman, the child
    pornography was contraband subject to seizure at the border.
    As contraband, the child pornography is also evidence of
    various crimes, including possession of child pornography,
    18 U.S.C. § 2252A(a)(5)(B), and importation of obscene
    material, 
    18 U.S.C. § 1462
    (a). But nothing in Cotterman
    authorized border officials to conduct a search for evidence
    that Cotterman was involved in sex-related crimes generally.
    Border officials are authorized to seize “merchandise
    which . . . shall have been introduced into the United States
    in any manner contrary to law.” 
    19 U.S.C. § 482
    (a)
    (emphasis added). The photos on Cotterman’s laptop
    computer were such merchandise. 
    18 U.S.C. § 2252
    (a). But
    border officials have no general authority to search for crime.
    This is true even if there is a possibility that such crimes may
    be perpetrated at the border in the future. So, for example, if
    U.S. officials reasonably suspect that a person who has
    presented himself at the border may be engaged in price
    fixing, see 
    15 U.S.C. § 1
    , they may not conduct a forensic
    search of his phone or laptop. Evidence of price fixing—
    texts or emails, for example—is not itself contraband whose
    importation is prohibited by law. Such emails may be
    evidence of a crime, but they are not contraband, and there is
    no law prohibiting the importation of mere evidence of crime.
    UNITED STATES V. CANO                               25
    We recognize that our analysis is in tension with the
    Fourth Circuit’s decision in Kolsuz. Kolsuz was detained at
    Washington Dulles International Airport when customs
    agents discovered firearm parts in his luggage. Kolsuz, 890
    F.3d at 138–39. Kolsuz was arrested and his cell phone
    seized. Id. at 139. The agents subjected the phone to a
    month-long forensic search, producing a 896-page report. Id.
    Kolsuz challenged the search, which the district court upheld
    and the Fourth Circuit affirmed. Id. at 139–42. The court
    approved the forensic search because the agents had “reason
    to believe . . . that Kolsuz was attempting to export firearms
    illegally” and that “their search would reveal not only
    evidence of the export violation they already had detected,
    but also ‘information related to other ongoing attempts to
    export illegally various firearm parts.’” Id. at 143 (quoting
    the district court; citation omitted). According to the Fourth
    Circuit, “[t]he justification behind the border search
    exception is broad enough to accommodate not only the
    direct interception of contraband as it crosses the border, but
    also the prevention and disruption of ongoing efforts to
    export contraband illegally.” Id. (emphasis added).10
    We agree with much of the Fourth Circuit’s discussion of
    foundational principles, but we respectfully disagree with the
    final step approving the search for further evidence that
    10
    As support for this proposition, the Fourth Circuit cited two district
    court cases originating within our circuit. Both of those cases addressed
    fact-patterns almost identical to Cano’s, and in each case the district court
    held that the border-search exception was not limited to searching for
    contraband directly. See United States v. Mendez, 
    240 F. Supp. 3d 1005
    ,
    1007–08 (D. Ariz. 2017); United States v. Ramos, 
    190 F. Supp. 3d 992
    ,
    999 (S.D. Cal. 2016). In neither case was the issue appealed to our circuit.
    Thus, Cano’s case presents the first opportunity for us to consider the
    matter.
    26                UNITED STATES V. CANO
    Kolsuz was smuggling weapons. Our disagreement focuses
    precisely on the critical question that we previously
    identified: Does the proper scope of a border search include
    the power to search for evidence of contraband that is not
    present at the border? Or, put differently, can border agents
    conduct a warrantless search for evidence of past or future
    border-related crimes? We think that the answer must be
    “no.” The “[d]etection of . . . contraband is the strongest
    historic rationale for the border-search exception.” Molina-
    Isidoro, 884 F.3d at 295 (Costa, J., specially concurring).
    Indeed, “every border-search case the Supreme Court has
    decided involved searches to locate items being smuggled”
    rather than evidence. Id. (emphasis added); see Montoya de
    Hernandez, 
    473 U.S. at 537
     (the border search is “to prevent
    the introduction of contraband into this country”); United
    States v. 12 200-Foot Reels of Super 8mm. Film, 
    413 U.S. 123
    , 125 (1973) (border searches are “necessary to prevent
    smuggling and to prevent prohibited articles from entry”);
    United States v. Thirty-Seven Photographs, 
    402 U.S. 363
    , 376
    (1971) (“Customs officers characteristically inspect luggage
    and their power to do so is not questioned in this case; it is an
    old practice and is intimately associated with excluding
    illegal articles from the country”). In fact, the Court has long
    “draw[n] a sharp distinction between searches for contraband
    and those for evidence that may reveal the importation of
    contraband.” Molina-Isidoro, 884 F.3d at 296 (Costa, J.,
    specially concurring).       The classic statement on the
    distinction between seizing goods at the border because their
    importation is prohibited and seizing goods at the border
    because they may be useful in prosecuting crimes is found in
    Boyd v. United States:
    Is a search and seizure, or, what is equivalent
    thereto, a compulsory production of a man’s
    UNITED STATES V. CANO                       27
    private papers, to be used in evidence against
    him in a proceeding to forfeit his property for
    alleged fraud against the revenue laws—is
    such a proceeding for such a purpose an
    “unreasonable search and seizure” within the
    meaning of the fourth amendment of the
    constitution? . . . . The search for and seizure
    of stolen or forfeited goods, or goods liable to
    duties and concealed to avoid the payment
    thereof, are totally different things from a
    search for and seizure of a man’s private
    books and papers for the purpose of obtaining
    information therein contained, or of using
    them as evidence against him. The two things
    differ toto coelo.
    
    116 U.S. 616
    , 622–23 (1886), overruled in part on other
    grounds by Warden, Md. Penitentiary v. Hayden, 
    387 U.S. 294
     (1967); see also id. at 633 (stating that compelling a man
    to produce the evidence against himself not only violates the
    Fifth Amendment, but makes the seizure of his “books and
    papers” unreasonable under the Fourth Amendment).
    Although we continue to acknowledge that “[t]he
    Government’s interest in preventing the entry of unwanted
    persons and effects is at its zenith at the international border”
    and that “the expectation of privacy is less at the border than
    it is in the interior,” Flores-Montano, 
    541 U.S. at 152, 154
    ,
    we hold that the border search exception authorizes
    warrantless searches of a cell phone only to determine
    whether the phone contains contraband. A broader search
    cannot be “justified by the particular purposes served by the
    exception.” Florida v. Royer, 
    460 U.S. 491
    , 500 (1983).
    28                UNITED STATES V. CANO
    2. The Impact of a Limited Scope for Border Searches
    Our conclusion that the border search exception is
    restricted in scope to searches for contraband implicates two
    practical limitations on warrantless border searches. First,
    border officials are limited to searching for contraband only;
    they may not search in a manner untethered to the search for
    contraband. The Supreme Court has repeatedly emphasized
    that “[t]he scope of the search must be ‘strictly tied to and
    justified by’ the circumstances which rendered its initiation
    permissible.” Terry v. Ohio, 
    392 U.S. 1
    , 19 (1968).
    The validity of the manual searches conducted by Agents
    Petonak and Medrano at their inception is beyond dispute.
    Manual searches of a cell phone at the border can be
    conducted without any suspicion whatsoever, see Cotterman,
    709 F.3d at 960, and both agents were officers of HSI and
    thus had authority to conduct border searches, Soto-Soto, 
    598 F.2d at
    548–49. As the Supreme Court explained in Terry,
    however, “a search which is reasonable at its inception may
    violate the Fourth Amendment by virtue of its intolerable
    intensity and scope.” 
    392 U.S. at 18
    .
    Once Cano was arrested, Agent Petonak briefly searched
    Cano’s phone and observed that there were no text messages.
    The observation that the phone contained no text messages
    falls comfortably within the scope of a search for digital
    contraband. Child pornography may be sent via text
    message, so the officers acted within the scope of a
    permissible border search in accessing the phone’s text
    messages.
    Agent Medrano conducted a second manual search of the
    phone log and text messages on Cano’s phone. Medrano,
    UNITED STATES V. CANO                            29
    however, did more than thumb through the phone consistent
    with a search for contraband. He also recorded phone
    numbers found in the call log, and he photographed two
    messages received after Cano had reached the border. Those
    actions have no connection whatsoever to digital contraband.
    Criminals may hide contraband in unexpected places, so it
    was reasonable for the two HSI officers to open the phone’s
    call log to verify that the log contained a list of phone
    numbers and not surreptitious images or videos. But the
    border search exception does not justify Agent Medrano’s
    recording of the phone numbers and text messages for further
    processing, because that action has no connection to ensuring
    that the phone lacks digital contraband. Accordingly, to the
    extent that Agent Medrano’s search of Cano’s phone went
    beyond a verification that the phone lacked digital
    contraband, the search exceeded the proper scope of a border
    search and was unreasonable as a border search under the
    Fourth Amendment.11
    11
    The fact of Cano’s arrest does not affect our analysis. The border
    search does not lose its identity as such once Cano was arrested. The
    United States retains a strong interest in preventing contraband from
    entering the United States, whether it is brought in inadvertently,
    smuggled, or admitted into the United States once its owner is arrested.
    See United States v. Ickes, 
    393 F.3d 501
    , 503–05 (4th Cir. 2005)
    (upholding the post-arrest search of a laptop computer at the border where
    the officials had reason to suspect the computer carried child
    pornography); see also United States v. Bates, 
    526 F.2d 966
    , 967–68 (5th
    Cir. 1976) (per curiam) (upholding a search of the defendant’s vehicle
    after he had been arrested at the border for violating his bond in
    connection with a previous drug crime under both the search incident to
    arrest and the border search exception).
    The government has not argued that the forensic search of Cano’s
    phone can be justified as a search incident to lawful arrest. Such an
    argument is foreclosed by Riley. See Riley, 573 U.S. at 388–91. Nor has
    30                  UNITED STATES V. CANO
    Second, because the border search exception is limited in
    scope to searches for contraband, border officials may
    conduct a forensic cell phone search only when they
    reasonably suspect that the cell phone contains contraband.
    We have held that a “highly intrusive” search—such as a
    forensic cell phone search—requires some level of
    particularized suspicion. Cotterman, 709 F.3d at 963, 968;
    see Flores-Montano, 
    541 U.S. at 152
    . But that just begs the
    question: Particularized suspicion of what? Contraband? Or
    evidence of future border-related crimes? Having concluded
    above 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, we think the answer here
    is clear: to conduct a more intrusive, forensic cell phone
    search border officials must reasonably suspect that the cell
    phone to be searched itself contains contraband.
    Were we to rule otherwise, the government could conduct
    a full forensic search of every electronic device of anyone
    arrested at the border, for the probable cause required to
    justify an arrest at the border will always satisfy the lesser
    reasonable suspicion standard needed to justify a forensic
    search. As the Court pointed out in Riley, modern cell phones
    are “minicomputers” with “immense storage capacity.” 573
    U.S. at 393. Such phones “carry a cache of sensitive personal
    information”—“[t]he sum of an individual’s private life”—
    such that a search of a cell phone may give the government
    the government argued that once Medrano saw the phone numbers in the
    call log and the text messages that he could record them consistent with
    the plain view exception. See United States v. Comprehensive Drug
    Testing, 
    621 F.3d 1162
    , 1175–77 (9th Cir. 2010) (en banc) (per curiam),
    overruled in part on other grounds as recognized by Demaree v.
    Pederson, 
    887 F.3d 870
    , 876 (9th Cir. 2018) (per curiam).
    UNITED STATES V. CANO                     31
    not only “sensitive records previously found in the home,”
    but a “broad array of private information never found in a
    home in any form—unless the phone is.” 
    Id.
     at 393–97.
    Were we to give the government unfettered access to cell
    phones, we would enable the government to evade the
    protections laid out in Riley “on the mere basis that [the
    searches] occurred at the border.” Soto-Soto, 
    598 F.2d at 549
    .
    Moreover, in cases such as this, where the individual
    suspected of committing the border-related crime has already
    been arrested, there is no reason why border officials cannot
    obtain a warrant before conducting their forensic search. This
    “is particularly true in light of ‘advances’ in technology that
    now permit ‘the more expeditious processing of warrant
    applications.’” Birchfield v. North Dakota, 
    136 S. Ct. 2160
    ,
    2192 (2016) (quoting Missouri v. McNeely, 
    569 U.S. 141
    , 154
    (2013)); see Riley, 573 U.S. at 401. Indeed, in most cases the
    time required to obtain a warrant would seem trivial
    compared to the hours, days, and weeks needed to complete
    a forensic electronic search. See, e.g., Wanjiku, 919 F.3d at
    477 (noting that a forensic “preview” takes one to three
    hours; the full examination “could take months”); Kolsuz, 890
    F.3d at 139 (describing how the forensic search “lasted for a
    full month, and yielded an 896-page report”); Cotterman, 709
    F.3d at 959 (describing how the first forensic search was
    conducted over five days; additional evidence was found
    “[o]ver the next few months”). We therefore conclude that
    border officials may conduct a forensic cell phone search
    only when they reasonably suspect that the cell phone to be
    searched itself contains contraband.
    Applied here, if the Cellebrite search of Cano’s cell phone
    qualifies as a forensic search, the entire search was
    32                    UNITED STATES V. CANO
    unreasonable under the Fourth Amendment.12 Although
    Agents Petonak and Medrano had reason to suspect that
    Cano’s phone would contain evidence leading to additional
    drugs, the record does not give rise to any objectively
    reasonable suspicion that the digital data in the phone
    contained contraband.13 Absent reasonable suspicion, the
    border search exception did not authorize the agents to
    conduct a warrantless forensic search of Cano’s phone, and
    evidence obtained through a forensic search should be
    suppressed.
    C. Good Faith Exception
    We next consider whether the evidence uncovered by the
    searches is nevertheless allowed by the good faith exception.
    Having held that the manual searches partially violated the
    Fourth Amendment and having held that, if the Cellebrite
    12
    Whether the Cellebrite search constitutes a forensic search is
    disputed. Because the district court passed on the issue without deciding
    it, because neither party has briefed the question to us, and because we are
    vacating Defendant’s conviction, we decline to reach the merits of the
    parties’ dispute. See ASSE Int’l, Inc. v. Kerry, 
    803 F.3d 1059
    , 1079 (9th
    Cir. 2015).
    13
    Indeed, the detection-of-contraband justification would rarely seem
    to apply to an electronic search of a cell phone outside the context of child
    pornography. The courts of appeals have just begun to confront the
    difficult questions attending cell phone searches at the border. Most of the
    cases have involved child pornography. See, e.g., Wanjiku, 
    919 F.3d 472
    ;
    Touset, 
    890 F.3d 1227
    ; Molina-Isidoro, 
    884 F.3d 287
    ; Vergara, 
    884 F.3d 1309
    ; Cotterman, 
    709 F.3d 952
    . Among the courts of appeals, only the
    Fourth Circuit has addressed the question outside the context of
    pornography. Kolsuz, 
    890 F.3d 133
     (exportation of firearms parts); see
    also United States v. Kim, 
    103 F. Supp. 3d 32
     (D.D.C. 2015) (exports in
    violation of Iranian trade embargo); United States v. Saboonchi, 
    990 F. Supp. 2d 536
     (D. Md. 2014) (same).
    UNITED STATES V. CANO                       33
    search of Cano’s phone was a forensic search, it violated the
    Fourth Amendment, we must determine whether the
    appropriate remedy is suppression of the evidence. The
    exclusionary rule is “a ‘prudential’ doctrine”; it is “‘not a
    personal constitutional right,’ nor is it designed to ‘redress the
    injury’ occasioned by an unconstitutional search.” Davis v.
    United States, 
    564 U.S. 229
    , 236 (2011) (quoting Stone v.
    Powell, 
    428 U.S. 465
    , 486 (1976)). Because “[e]xclusion
    exacts a heavy toll on both the judicial system and society at
    large,” we invoke the rule when we are confident that it will
    “deter future Fourth Amendment violations.” 
    Id.
     at 236–37.
    The exclusionary rule does not deter such violations “when
    the police conduct a search in objectively reasonable reliance
    on binding judicial precedent.” Id. at 239. We have said that
    the good faith exception applies only to searches where
    “binding appellate precedent . . . ‘specifically authorizes’ the
    police’s search.” United States v. Lara, 
    815 F.3d 605
    , 613
    (9th Cir. 2016) (quoting Davis, 
    564 U.S. at 232
    ). It is not
    sufficient for the question to be “unclear” or for the
    government’s position to be “plausibly . . . permissible.” 
    Id.
    at 613–14. At the same time, the “precedent [does not have]
    to constitute a factual match with the circumstances of the
    search in question for the good-faith exception to apply” so
    as not to “make the good-faith exception a nullity.” United
    States v. Lustig, 
    830 F.3d 1075
    , 1082 (9th Cir. 2016).
    The government points to Cotterman as support for the
    good faith of the officials. We fail to see how border officials
    could believe that Cotterman was “binding appellate
    precedent” authorizing their search. Although we have
    concluded that Cotterman is still good law after Riley, the
    officials could not rely on Cotterman to justify a search for
    evidence; Cotterman was a search for contraband that the
    government has a right to seize at the border. Here, the
    34                UNITED STATES V. CANO
    officials’ search was objectively tied only to proving their
    case against Cano and finding evidence of future crimes.
    Searching for evidence and searching for contraband are not
    the same thing.
    We understand that border officials might have thought
    that their actions were reasonable, and we recognize that
    border officials have to make in-the-moment decisions about
    how to conduct their business—whether or not they have
    written guidance from the courts. But as we understand the
    Davis rule, the good faith exception to the exclusionary rule
    applies only when the officials have relied on “binding
    appellate precedent.” See Lara, 815 F.3d at 613; see also
    Wanjiku, 919 F.3d at 485–86 (finding that agents had
    reasonable suspicion to search the defendant’s cell phone,
    laptop, and portable hard drive for child pornography;
    holding that, if probable cause was required, the officials
    acted in good faith). This is a rapidly developing area, not an
    area of settled law. Even if our decision in Cotterman
    rendered the searches “plausibly . . . permissible,” it did not
    “specifically authorize” the cell phone searches at issue here.
    Lara, 815 F.3d at 613–14.
    ***
    In sum, the manual searches and the Cellebrite search of
    Cano’s cell phone exceeded the scope of a valid border
    search. Because the good faith exception does not apply,
    most of the evidence obtained from the searches of Cano’s
    cell phone should have been suppressed. We thus reverse the
    district court’s order denying Cano’s motion to suppress, and
    we vacate Cano’s conviction. On any retrial, the district court
    should determine whether any additional evidence from the
    warrantless searches of Cano’s cell phone should be
    UNITED STATES V. CANO                       35
    suppressed, either because the Cellebrite search qualifies as
    a forensic search, which the government lacked reasonable
    suspicion to conduct, or because the evidence exceeds the
    proper scope of a border search.
    III. DISCOVERY ISSUES
    Cano has also alleged that the government violated his
    rights under both Brady and Federal Rule of Criminal
    Procedure 16 when it failed to turn over certain information
    that Cano requested from the FBI and DEA. We address
    Cano’s discovery claims, as the issues may be relevant on any
    retrial.
    Under Brady, the prosecution has an obligation, imposed
    by the Due Process Clause, to produce “evidence favorable to
    an accused upon request . . . where the evidence is material
    either to guilt or to punishment.” 
    373 U.S. at 87
    .
    “[E]vidence is material only if there is a reasonable
    probability that, had the evidence been disclosed to the
    defense, the result of the proceeding would have been
    different.” United States v. Bagley, 
    473 U.S. 667
    , 682
    (1985).14
    Under Rule 16, the government must, upon request, turn
    over any documents “within the government’s possession,
    custody, or control” that are “material to preparing the
    defense.” Fed. R. Crim. P. 16(a)(1)(E)(i). The defendant
    “must make a threshold showing of materiality, which
    requires a presentation of facts which would tend to show that
    the Government is in possession of information helpful to the
    14
    We review de novo whether a Brady violation has occurred.
    United States v. Stever, 
    603 F.3d 747
    , 752 (9th Cir. 2010).
    36                  UNITED STATES V. CANO
    defense.” United States v. Muniz-Jaquez, 
    718 F.3d 1180
    ,
    1183–84 (9th Cir. 2013) (quoting United States v. Stever, 
    603 F.3d 747
    , 752 (9th Cir. 2010)). Because “[i]nformation that
    is not exculpatory or impeaching may still be relevant to
    developing a possible defense,” Rule 16 is “broader than
    Brady.” Id. at 1183.15
    Under both Brady and Rule 16, the government “has no
    obligation to produce information which it does not possess
    or of which it is unaware.” Sanchez v. United States, 
    50 F.3d 1448
    , 1453 (9th Cir. 1995). It has an obligation to turn over
    only material, exculpatory or otherwise helpful to the defense,
    that it has in its possession.16 “Possession” is not limited to
    what the prosecutor personally knows. Browning v. Baker,
    
    875 F.3d 444
    , 460 (9th Cir. 2017), cert. denied, 
    138 S. Ct. 2608
     (2018); United States v. Bryan, 
    868 F.2d 1032
    , 1036
    (9th Cir. 1989). Because prosecutors are in a “unique
    position to obtain information known to other agents of the
    government,” they have an obligation to “disclos[e] what
    [they] do[] not know but could have learned.” Carriger v.
    Stewart, 
    132 F.3d 463
    , 480 (9th Cir. 1997) (en banc); see also
    Kyles v. Whitley, 
    514 U.S. 419
    , 437 (1995) (describing how
    15
    Although discovery rulings are generally reviewed for abuse of
    discretion, Stever, 
    603 F.3d at 752
    , we review a district court’s
    interpretation of the discovery rules de novo, United States v. Cedano-
    Arellano, 
    332 F.3d 568
    , 570–71 (9th Cir. 2003).
    16
    The “possession” element of Brady is treated as coextensive with
    that of Rule 16. See, e.g., United States v. Bryan, 
    868 F.2d 1032
    , 1037
    (9th Cir. 1989) (using the same “knowledge and access” test to determine
    “possession” for both Rule 16 and Brady); United States v. Grace, 
    401 F. Supp. 2d 1069
    , 1076 (D. Mont. 2005) (“Whether exculpatory information
    is in the government’s possession for Brady purposes is measured by the
    same . . . test used under Rule 16(a)(1)(E) for discovery.”).
    UNITED STATES V. CANO                       37
    the “individual prosecutor has a duty to learn of any favorable
    evidence known to [those] acting on the government’s
    behalf”); Youngblood v. West Virginia, 
    547 U.S. 867
    , 869–70
    (2006) (per curiam). This includes information held by
    subordinates such as investigating police officers, see Kyles,
    
    514 U.S. at 438
    ; United States v. Price, 
    566 F.3d 900
    , 908–09
    (9th Cir. 2009), and sometimes extends to information held
    by other executive branch agencies, see United States v.
    Santiago, 
    46 F.3d 885
    , 893 (9th Cir. 1995); United States v.
    Jennings, 
    960 F.2d 1488
    , 1490–91 (9th Cir. 1992).
    Documents held by another executive branch agency are
    deemed to be “in the possession of the government” if the
    prosecutor has “knowledge of and access to” the documents.
    Bryan, 
    868 F.2d at 1036
    . Knowledge and access are
    presumed if the agency participates in the investigation of the
    defendant. 
    Id.
     (“The prosecutor will be deemed to have
    knowledge of and access to anything in the possession,
    custody or control of any federal agency participating in the
    same investigation of the defendant.”). However, “a federal
    prosecutor need not comb the files of every federal agency
    which might have documents regarding the defendant in order
    to fulfill his or her obligations under [Rule 16].” Id.; see also
    Kyles, 
    514 U.S. at 437
     (“We have never held that the
    Constitution demands an open file policy . . . .”).
    Here, Cano asserted a third-party defense theory: he was
    staying in Tijuana with his cousin, Jose Medina; Medina was
    a member of the Latin Kings gang which was involved in the
    drug trade; and Medina had access to Cano’s car before Cano
    was stopped at the border. Cano requested that the U.S.
    Attorney’s Office turn over any material held by HSI, the
    FBI, and the DEA relating to: (1) records linking his cousin
    Jose Medina to drug sales, distribution, and trafficking; and
    38                UNITED STATES V. CANO
    (2) documentation showing a link between the Latin Kings
    and drug trafficking through the United States-Mexico
    border. The district court found that both requests might
    produce evidence that was exculpatory under Brady and
    material under Rule 16, but limited Cano’s discovery to only
    material held by HSI. The court concluded that the
    prosecutor did not have access to evidence held by the FBI
    and DEA, and thus had no obligation to provide such
    evidence, because both agencies had “rebuffed” the
    prosecutor’s attempts to obtain information. Thus, the only
    issue raised on appeal is whether any material held by the
    DEA and FBI should be deemed “within the government’s
    possession.”
    We find no evidence that the prosecution had knowledge
    or possession of evidence showing that Medina or the Latin
    Kings were involved in drug trafficking at the Mexico-
    California border. Medina had one drug-related conviction,
    and it was for simple possession of cocaine, not trafficking.
    Before trial, however, the prosecution team reached out to
    Medina and promised him immunity and immigration
    documents in exchange for cooperation and information
    concerning drug importation. Although Medina originally
    rebuffed the government, he eventually offered to work with
    the government and “stated that he would be able to assist the
    Government with the . . . biggest RICO . . . case and drug
    seizures of 20 to 25 kilograms at a time.” The district court
    found that Medina’s statements “spawn[ed] an inference that
    [he] is closely connected to the drug-traffickers in Tijuana.”
    Based on this inference, Cano argues that the government had
    sufficient knowledge of a possible connection between
    Medina and drug trafficking to trigger the government’s
    discovery obligations.
    UNITED STATES V. CANO                            39
    Cano’s argument, however, misstates the test we first set
    out in Bryan. Cano has argued only that the prosecutor had
    knowledge that certain facts might exist. However, we have
    said that the prosecutor’s disclosure obligations turn on “the
    extent to which the prosecutor has knowledge of and access
    to the documents sought by the defendant.” Bryan, 
    868 F.2d at 1036
     (emphasis added); see also Santiago, 
    46 F.3d at 894
    (analyzing whether the prosecutor had knowledge of and
    access to certain inmate files). We have required disclosure
    only of documents that the prosecutor knew existed. Bryan,
    
    868 F.2d at
    1034–37.
    Here, although Cano has presented evidence alleging a
    plausible connection between Medina and drug trafficking,
    Cano has failed to adduce any evidence showing that
    prosecutors or investigators knew that the FBI or the DEA
    possessed documents showing that connection. In fact, the
    record established the opposite. One of the HSI agents ran
    Medina’s name through two different law enforcement
    clearinghouses—in which the FBI and DEA both
    participate—and neither search returned any hits.
    Moreover, the prosecutor did not have access to FBI or
    DEA files and thus was under no obligation to “comb the
    files” of the FBI and DEA for documents relating to
    Medina.17 We have occasionally presumed that a prosecutor
    17
    Cano sought to introduce a 2015 report from the FBI’s National
    Gang Intelligence Center listing the Latin Kings as one of the top gangs
    involved in cross border crime, and including drug importation in its list
    of cross-border crimes. (The evidence was not ultimately presented at
    trial.) Cano also proffered information concerning two government
    informants working within the Latin Kings. Although these reports may
    suggest that the FBI may have had further information regarding a
    connection between the Latin Kings and drug importation, Cano has not
    40                   UNITED STATES V. CANO
    has access to an agency’s files where the prosecutor actually
    obtained inculpatory information from the agency, even if the
    agency was not involved in the investigation or prosecution.
    See Santiago, 
    46 F.3d at 894
     (concluding that the prosecutor
    had access to other inmates’ prison files where the prosecutor
    was able to obtain the defendant’s prison file from the Bureau
    of Prisons). Here, however, the U.S. Attorney’s Office
    advised the district court that it did not obtain any evidence—
    inculpatory or exculpatory—from the FBI or the DEA.
    Following the district court’s initial discovery order, HSI’s
    agent—Agent Petonak—made a formal request to the legal
    counsel for the FBI and the DEA for any “materials related to
    the Latin Kings importing cocaine from Mexico to the United
    States,” but both agencies “declined to provide [him] with
    any such information.” Neither agency revealed whether any
    such information existed or provided a reason for its refusal.
    The U.S. Attorney’s Office also reached out to the FBI and
    the DEA for Latin Kings-related discovery. That request was
    also denied.
    Cano argues that the FBI and DEA’s refusal to turn over
    information in this particular case should not be
    determinative and that the test for access under Bryan and
    Santiago requires only that the U.S. Attorney’s Office or
    investigating agency generally have access to this type of
    information. Cano points to evidence from both prosecution
    and defense witnesses that HSI regularly works with the FBI
    and the DEA; that “interagency cooperation has been
    emphasized” after September 11, 2001; that agents from the
    different agencies regularly access information for one
    another; that a DEA representative worked in Agent
    Petonak’s office; and that agents are often cross-listed
    established that the prosecutor had access to the FBI’s or the DEA’s files.
    UNITED STATES V. CANO                      41
    between agencies. From this, Cano argues that HSI generally
    has access to FBI and DEA files for inculpatory purposes,
    and thus asserts that the refusal of the FBI and DEA to
    provide information in this particular case should not relieve
    HSI of its discovery obligations. To rule otherwise, Cano
    contends, would allow these withholding agencies “to
    effectively wall off exculpatory information from the
    government in a particular defendant’s case, all the while
    providing the government free-flowing access to information
    in its overall investigations.”
    Although we are sympathetic to Cano’s concerns
    regarding strategic withholding, the rule Cano urges us to
    adopt is much too broad. Brady and Rule 16 obligations are
    case specific. In Bryan we stated that the test for
    “possession” turns on the prosecutor’s “knowledge of and
    access to the documents sought by the defendant in each
    case” and that “[t]he prosecutor will be deemed to have
    knowledge of and access to anything in the possession,
    custody or control of any federal agency participating in the
    same investigation of the defendant.” 
    868 F.2d at 1036
    (emphases added). Such a case-by-case approach makes
    sense, as the FBI and DEA may have valid concerns over
    revealing sensitive information in cases wholly unrelated to
    the agencies’ own workload; the agencies may be reluctant to
    cooperate in a particular investigation if it means opening
    their files in other investigations. If Cano thinks that the FBI
    or the DEA have other information, not known to the U.S.
    Attorney’s Office or the investigating officers, he may file a
    request under the Freedom of Information Act, subject to that
    Act’s own restrictions on releasing “records or information
    compiled for law enforcement purposes.” 
    5 U.S.C. § 552
    (b)(7). Brady and Rule 16 are not a means for a
    defendant to require the prosecutor to do this work for him.
    42                UNITED STATES V. CANO
    See generally Roth v. U.S. Dep’t of Justice, 
    642 F.3d 1161
    ,
    1175–76 (D.C. Cir. 2011); Boyd v. Crim. Div. of U.S. Dep’t
    of Justice, 
    475 F.3d 381
    , 386–89 (D.C. Cir. 2007).
    Cano is unable to identify any case in which the
    prosecutor was required to obtain discovery from an agency
    wholly unrelated to the investigation of the defendant in spite
    of that agency’s refusal to comply; all of the cases cited by
    Cano imposing a “duty to learn” on the prosecutor involve
    independent federal agencies that had participated in the
    investigation of the defendant. See Price, 
    566 F.3d at
    908–09; Carriger, 
    132 F.3d at
    479–80; United States v.
    Perdomo, 
    929 F.2d 967
    , 971 (3d Cir. 1991); United States v.
    Osorio, 
    929 F.2d 753
    , 762 (1st Cir. 1991). Indeed, the Third
    Circuit has held that a Brady obligation is not triggered where
    the agency did not participate in the investigation in any way,
    did not share any information with the prosecuting team, and
    where the prosecutor had no authority or control over the
    agency’s members. United States v. Pelullo, 
    399 F.3d 197
    ,
    218 (3d Cir. 2005); see also United States v. Salyer, 
    271 F.R.D. 148
    , 156 (E.D. Cal. 2010) (concluding that “[t]he need
    for formal process in the acquisition of documents [from
    another agency] is the antithesis of ‘access’”). We similarly
    now hold that the prosecutor should not be held to have
    “access” to any information that an agency not involved in
    the investigation or prosecution of the case refuses to turn
    over.
    Because the HSI agents and prosecutors in Cano’s case
    neither knew of nor had access to any additional files relating
    to Medina and the Latin Kings, we conclude that the
    government has satisfied its discovery obligations under
    Brady and Rule 16.
    UNITED STATES V. CANO               43
    IV. CONCLUSION
    We REVERSE the district court’s order denying Cano’s
    motion to suppress and VACATE Cano’s conviction.