(Slip Opinion)
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` OCTOBER TERM, 2013
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`Syllabus
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`1
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` NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
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` being done in connection with this case, at the time the opinion is issued.
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` The syllabus constitutes no part of the opinion of the Court but has been
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` prepared by the Reporter of Decisions for the convenience of the reader.
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` See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.
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`SUPREME COURT OF THE UNITED STATES
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` Syllabus
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` RILEY v. CALIFORNIA
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`CERTIORARI TO THE COURT OF APPEAL OF CALIFORNIA,
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`
`
` FOURTH APPELLATE DISTRICT, DIVISION ONE
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`No. 13–132. Argued April 29, 2014—Decided June 25, 2014*
`
`In No. 13–132, petitioner Riley was stopped for a traffic violation,
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`which eventually led to his arrest on weapons charges. An officer
`searching Riley incident to the arrest seized a cell phone from Riley’s
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`pants pocket. The officer accessed information on the phone and no-
`ticed the repeated use of a term associated with a street gang. At the
`police station two hours later, a detective specializing in gangs fur-
`ther examined the phone’s digital contents. Based in part on photo-
`graphs and videos that the detective found, the State charged Riley
`in connection with a shooting that had occurred a few weeks earlier
`and sought an enhanced sentence based on Riley’s gang membership.
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`Riley moved to suppress all evidence that the police had obtained
`from his cell phone. The trial court denied the motion, and Riley was
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`convicted. The California Court of Appeal affirmed.
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`In No. 13–212, respondent Wurie was arrested after police ob-
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`served him participate in an apparent drug sale. At the police sta-
`tion, the officers seized a cell phone from Wurie’s person and noticed
`that the phone was receiving multiple calls from a source identified
`as “my house” on its external screen. The officers opened the phone,
`accessed its call log, determined the number associated with the “my
`house” label, and traced that number to what they suspected was
`Wurie’s apartment. They secured a search warrant and found drugs,
`a firearm and ammunition, and cash in the ensuing search. Wurie
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`was then charged with drug and firearm offenses. He moved to sup-
`press the evidence obtained from the search of the apartment. The
`District Court denied the motion, and Wurie was convicted. The
`——————
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`*Together with No. 13–212, United States v. Wurie, on certiorari to
`the United States Court of Appeals for the First Circuit.
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`RILEY v. CALIFORNIA
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`Syllabus
`First Circuit reversed the denial of the motion to suppress and vacat-
`ed the relevant convictions.
`Held: The police generally may not, without a warrant, search digital
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`information on a cell phone seized from an individual who has been
`arrested. Pp. 5–28.
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`(a) A warrantless search is reasonable only if it falls within a spe-
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`cific exception to the Fourth Amendment’s warrant requirement. See
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`Kentucky v. King, 563 U. S. ___, ___. The well-established exception
`at issue here applies when a warrantless search is conducted incident
`to a lawful arrest.
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`Three related precedents govern the extent to which officers may
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`search property found on or near an arrestee. Chimel v. California,
`395 U. S. 752, requires that a search incident to arrest be limited to
`the area within the arrestee’s immediate control, where it is justified
`by the interests in officer safety and in preventing evidence destruc-
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`tion. In United States v. Robinson, 414 U. S. 218, the Court applied
`the Chimel analysis to a search of a cigarette pack found on the ar-
`restee’s person. It held that the risks identified in Chimel are pre-
`sent in all custodial arrests, 414 U. S., at 235, even when there is no
`specific concern about the loss of evidence or the threat to officers in a
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`particular case, id., at 236. The trilogy concludes with Arizona v.
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`Gant, 556 U. S. 332, which permits searches of a car where the ar-
`restee is unsecured and within reaching distance of the passenger
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`compartment, or where it is reasonable to believe that evidence of the
`crime of arrest might be found in the vehicle, id., at 343. Pp. 5–8.
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`(b) The Court declines to extend Robinson’s categorical rule to
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`searches of data stored on cell phones. Absent more precise guidance
`from the founding era, the Court generally determines whether to ex-
`empt a given type of search from the warrant requirement “by as-
`sessing, on the one hand, the degree to which it intrudes upon an in-
`dividual’s privacy and, on the other, the degree to which it is needed
`for the promotion of legitimate governmental interests.” Wyoming v.
`Houghton, 526 U. S. 295, 300. That balance of interests supported
`the search incident to arrest exception in Robinson. But a search of
`digital information on a cell phone does not further the government
`interests identified in Chimel, and implicates substantially greater
`individual privacy interests than a brief physical search. Pp. 8–22.
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`(1) The digital data stored on cell phones does not present either
`Chimel risk. Pp. 10–15.
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`(i) Digital data stored on a cell phone cannot itself be used as a
`weapon to harm an arresting officer or to effectuate the arrestee’s es-
`cape. Officers may examine the phone’s physical aspects to ensure
`that it will not be used as a weapon, but the data on the phone can
`endanger no one. To the extent that a search of cell phone data
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`Cite as: 573 U. S. ____ (2014)
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`Syllabus
`might warn officers of an impending danger, e.g., that the arrestee’s
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`confederates are headed to the scene, such a concern is better ad-
`dressed through consideration of case-specific exceptions to the war-
`rant requirement, such as exigent circumstances. See, e.g., Warden,
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`Md. Penitentiary v. Hayden, 387 U. S. 294, 298–299. Pp. 10–12.
`(ii) The United States and California raise concerns about the
`destruction of evidence, arguing that, even if the cell phone is physi-
`cally secure, information on the cell phone remains vulnerable to re-
`mote wiping and data encryption. As an initial matter, those broad
`concerns are distinct from Chimel’s focus on a defendant who re-
`sponds to arrest by trying to conceal or destroy evidence within his
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`reach. The briefing also gives little indication that either problem is
`prevalent or that the opportunity to perform a search incident to ar-
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`rest would be an effective solution. And, at least as to remote wiping,
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`law enforcement currently has some technologies of its own for com-
`batting the loss of evidence. Finally, law enforcement’s remaining
`concerns in a particular case might be addressed by responding in a
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`targeted manner to urgent threats of remote wiping, see Missouri v.
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`McNeely, 569 U. S. ___, ___, or by taking action to disable a phone’s
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`locking mechanism in order to secure the scene, see Illinois v. McAr-
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`thur, 531 U. S. 326, 331–333. Pp. 12–15.
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`(2) A conclusion that inspecting the contents of an arrestee’s
`pockets works no substantial additional intrusion on privacy beyond
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`the arrest itself may make sense as applied to physical items, but
`more substantial privacy interests are at stake when digital data is
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`involved. Pp. 15–22.
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`(i) Cell phones differ in both a quantitative and a qualitative
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`sense from other objects that might be carried on an arrestee’s per-
`son. Notably, modern cell phones have an immense storage capacity.
`Before cell phones, a search of a person was limited by physical reali-
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`ties and generally constituted only a narrow intrusion on privacy.
`But cell phones can store millions of pages of text, thousands of pic-
`tures, or hundreds of videos. This has several interrelated privacy
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`consequences. First, a cell phone collects in one place many distinct
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`types of information that reveal much more in combination than any
`isolated record. Second, the phone’s capacity allows even just one
`type of information to convey far more than previously possible.
`Third, data on the phone can date back for years. In addition, an el-
`ement of pervasiveness characterizes cell phones but not physical
`records. A decade ago officers might have occasionally stumbled
`across a highly personal item such as a diary, but today many of the
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`more than 90% of American adults who own cell phones keep on their
`person a digital record of nearly every aspect of their lives. Pp. 17–
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`21.
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` RILEY v. CALIFORNIA
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`Syllabus
`(ii) The scope of the privacy interests at stake is further com-
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` plicated by the fact that the data viewed on many modern cell phones
`may in fact be stored on a remote server. Thus, a search may extend
`well beyond papers and effects in the physical proximity of an ar-
`restee, a concern that the United States recognizes but cannot defini-
`tively foreclose. Pp. 21–22.
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`(c) Fallback options offered by the United States and California are
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`flawed and contravene this Court’s general preference to provide
`clear guidance to law enforcement through categorical rules. See
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`Michigan v. Summers, 452 U. S. 692, 705, n. 19. One possible rule is
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`to import the Gant standard from the vehicle context and allow a
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`warrantless search of an arrestee’s cell phone whenever it is reason-
`able to believe that the phone contains evidence of the crime of ar-
`rest. That proposal is not appropriate in this context, and would
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`prove no practical limit at all when it comes to cell phone searches.
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`Another possible rule is to restrict the scope of a cell phone search to
`information relevant to the crime, the arrestee’s identity, or officer
`safety. That proposal would again impose few meaningful con-
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`straints on officers. Finally, California suggests an analogue rule,
`under which officers could search cell phone data if they could have
`obtained the same information from a pre-digital counterpart. That
`proposal would allow law enforcement to search a broad range of
`items contained on a phone even though people would be unlikely to
`carry such a variety of information in physical form, and would
`launch courts on a difficult line-drawing expedition to determine
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`which digital files are comparable to physical records. Pp. 22–25.
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`(d) It is true that this decision will have some impact on the ability
`of law enforcement to combat crime. But the Court’s holding is not
`that the information on a cell phone is immune from search; it is that
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`a warrant is generally required before a search. The warrant re-
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`quirement is an important component of the Court’s Fourth Amend-
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`ment jurisprudence, and warrants may be obtained with increasing
`efficiency. In addition, although the search incident to arrest excep-
`tion does not apply to cell phones, the continued availability of the ex-
`igent circumstances exception may give law enforcement a justifica-
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`tion for a warrantless search in particular cases. Pp. 25–27.
`No. 13–132, reversed and remanded; No. 13–212, 728 F. 3d 1, affirmed.
`ROBERTS, C. J., delivered the opinion of the Court, in which SCALIA,
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`KENNEDY, THOMAS, GINSBURG, BREYER, SOTOMAYOR, and KAGAN, JJ.,
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`joined. ALITO, J., filed an opinion concurring in part and concurring in
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`the judgment.
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` Cite as: 573 U. S. ____ (2014)
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`Opinion of the Court
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`1
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` NOTICE: This opinion is subject to formal revision before publication in the
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` preliminary print of the United States Reports. Readers are requested to
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` notify the Reporter of Decisions, Supreme Court of the United States, Wash-
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` ington, D. C. 20543, of any typographical or other formal errors, in order
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` that corrections may be made before the preliminary print goes to press.
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`SUPREME COURT OF THE UNITED STATES
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`13–132
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`_________________
` Nos. 13–132 and 13–212
`_________________
`DAVID LEON RILEY, PETITIONER
`
`v.
`CALIFORNIA
`ON WRIT OF CERTIORARI TO THE COURT OF APPEAL OF CALI-
`FORNIA, FOURTH APPELLATE DISTRICT, DIVISION ONE
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`
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`UNITED STATES, PETITIONER
`
`v.
`BRIMA WURIE
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`ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF
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`
`APPEALS FOR THE FIRST CIRCUIT
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`[June 25, 2014]
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` CHIEF JUSTICE ROBERTS delivered the opinion of the
`Court.
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`These two cases raise a common question: whether the
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`police may, without a warrant, search digital information
`on a cell phone seized from an individual who has been
`arrested.
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`13–212
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`I
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`A
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`In the first case, petitioner David Riley was stopped by a
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`police officer for driving with expired registration tags. In
`the course of the stop, the officer also learned that Riley’s
`license had been suspended. The officer impounded Ri-
`ley’s car, pursuant to department policy, and another
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` RILEY v. CALIFORNIA
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`Opinion of the Court
`officer conducted an inventory search of the car. Riley was
`arrested for possession of concealed and loaded firearms
`when that search turned up two handguns under the car’s
`hood. See Cal. Penal Code Ann. §§12025(a)(1), 12031(a)(1)
`(West 2009).
`
`An officer searched Riley incident to the arrest and
`found items associated with the “Bloods” street gang. He
`also seized a cell phone from Riley’s pants pocket. Accord-
`ing to Riley’s uncontradicted assertion, the phone was a
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`“smart phone,” a cell phone with a broad range of other
`functions based on advanced computing capability, large
`storage capacity, and Internet connectivity. The officer
`accessed information on the phone and noticed that some
`words (presumably in text messages or a contacts list)
`were preceded by the letters “CK”—a label that, he be-
`lieved, stood for “Crip Killers,” a slang term for members
`of the Bloods gang.
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`At the police station about two hours after the arrest, a
`detective specializing in gangs further examined the con-
`tents of the phone. The detective testified that he “went
`through” Riley’s phone “looking for evidence, because . . .
`gang members will often video themselves with guns or
`take pictures of themselves with the guns.” App. in No.
`13–132, p. 20. Although there was “a lot of stuff ” on the
`phone, particular files that “caught [the detective’s] eye”
`included videos of young men sparring while someone
`yelled encouragement using the moniker “Blood.” Id., at
`11–13. The police also found photographs of Riley stand-
`ing in front of a car they suspected had been involved in a
`shooting a few weeks earlier.
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`Riley was ultimately charged, in connection with that
`earlier shooting, with firing at an occupied vehicle, assault
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`with a semiautomatic firearm, and attempted murder.
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`The State alleged that Riley had committed those crimes
`for the benefit of a criminal street gang, an aggravating
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`factor that carries an enhanced sentence. Compare Cal.
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`Opinion of the Court
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` Penal Code Ann. §246 (2008) with §186.22(b)(4)(B) (2014).
`Prior to trial, Riley moved to suppress all evidence that
`the police had obtained from his cell phone. He contended
`that the searches of his phone violated the Fourth
`Amendment, because they had been performed without a
`warrant and were not otherwise justified by exigent cir-
`cumstances. The trial court rejected that argument. App.
`
`in No. 13–132, at 24, 26. At Riley’s trial, police officers
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`testified about the photographs and videos found on the
`phone, and some of the photographs were admitted into
`evidence. Riley was convicted on all three counts and
`received an enhanced sentence of 15 years to life in prison.
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`The California Court of Appeal affirmed. No. D059840
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`(Cal. App., Feb. 8, 2013), App. to Pet. for Cert. in No. 13–
`132, pp. 1a–23a. The court relied on the California Su-
`preme Court’s decision in People v. Diaz, 51 Cal. 4th 84,
`244 P. 3d 501 (2011), which held that the Fourth Amend-
`ment permits a warrantless search of cell phone data
`incident to an arrest, so long as the cell phone was imme-
`diately associated with the arrestee’s person. See id., at
`93, 244 P. 3d, at 505–506.
`
`The California Supreme Court denied Riley’s petition for
`review, App. to Pet. for Cert. in No. 13–132, at 24a, and we
`granted certiorari, 571 U. S. ___ (2014).
`B
`In the second case, a police officer performing routine
`
`
`surveillance observed respondent Brima Wurie make an
`apparent drug sale from a car. Officers subsequently
`arrested Wurie and took him to the police station. At the
`station, the officers seized two cell phones from Wurie’s
`person. The one at issue here was a “flip phone,” a kind of
`phone that is flipped open for use and that generally has a
`smaller range of features than a smart phone. Five to ten
`minutes after arriving at the station, the officers noticed
`that the phone was repeatedly receiving calls from a
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` RILEY v. CALIFORNIA
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`Opinion of the Court
`source identified as “my house” on the phone’s external
`screen. A few minutes later, they opened the phone and
`saw a photograph of a woman and a baby set as the
`phone’s wallpaper. They pressed one button on the phone
`to access its call log, then another button to determine the
`phone number associated with the “my house” label. They
`next used an online phone directory to trace that phone
`number to an apartment building.
`
`
`When the officers went to the building, they saw Wurie’s
`name on a mailbox and observed through a window a
`woman who resembled the woman in the photograph on
`Wurie’s phone. They secured the apartment while obtain-
`
`ing a search warrant and, upon later executing the war-
`rant, found and seized 215 grams of crack cocaine, mari-
`juana, drug paraphernalia, a firearm and ammunition, and
`cash.
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`Wurie was charged with distributing crack cocaine,
`possessing crack cocaine with intent to distribute, and
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`being a felon in possession of a firearm and ammunition.
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`See 18 U. S. C. §922(g); 21 U. S. C. §841(a). He moved to
`suppress the evidence obtained from the search of the
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`apartment, arguing that it was the fruit of an unconstitu-
`tional search of his cell phone. The District Court denied
`the motion. 612 F. Supp. 2d 104 (Mass. 2009). Wurie was
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`convicted on all three counts and sentenced to 262 months
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`in prison.
`
`A divided panel of the First Circuit reversed the denial
`of Wurie’s motion to suppress and vacated Wurie’s convic-
`tions for possession with intent to distribute and posses-
`sion of a firearm as a felon. 728 F. 3d 1 (2013). The court
`held that cell phones are distinct from other physical
`possessions that may be searched incident to arrest with-
`out a warrant, because of the amount of personal data cell
`phones contain and the negligible threat they pose to law
`enforcement interests. See id., at 8–11.
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`We granted certiorari. 571 U. S. ___ (2014).
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` Cite as: 573 U. S. ____ (2014)
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`Opinion of the Court
`
` II
`The Fourth Amendment provides:
`
`“The right of the people to be secure in their per-
`sons, houses, papers, and effects, against unreasona-
`ble searches and seizures, shall not be violated, and
`no Warrants shall issue, but upon probable cause,
`supported by Oath or affirmation, and particularly
`describing the place to be searched, and the persons or
`things to be seized.”
`As the text makes clear, “the ultimate touchstone of the
`
`
`Fourth Amendment is ‘reasonableness.’” Brigham City v.
`Stuart, 547 U. S. 398, 403 (2006). Our cases have deter-
`mined that “[w]here a search is undertaken by law en-
`forcement officials to discover evidence of criminal wrong-
`doing, . . . reasonableness generally requires the obtaining
`of a judicial warrant.” Vernonia School Dist. 47J v. Acton,
`515 U. S. 646, 653 (1995). Such a warrant ensures that
`the inferences to support a search are “drawn by a neutral
`and detached magistrate instead of being judged by the
`officer engaged in the often competitive enterprise of
`ferreting out crime.” Johnson v. United States, 333 U. S.
`10, 14 (1948). In the absence of a warrant, a search is
`reasonable only if it falls within a specific exception to the
`warrant requirement. See Kentucky v. King, 563 U. S.
`___, ___ (2011) (slip op., at 5–6).
`
`The two cases before us concern the reasonableness of a
`warrantless search incident to a lawful arrest. In 1914,
`this Court first acknowledged in dictum “the right on the
`part of the Government, always recognized under English
`and American law, to search the person of the accused
`when legally arrested to discover and seize the fruits or
`evidences of crime.” Weeks v. United States, 232 U. S. 383,
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`392. Since that time, it has been well accepted that such a
`search constitutes an exception to the warrant require-
`ment.
`Indeed, the label “exception” is something of a
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` RILEY v. CALIFORNIA
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`Opinion of the Court
`misnomer in this context, as warrantless searches incident
`to arrest occur with far greater frequency than searches
`conducted pursuant to a warrant. See 3 W. LaFave,
`Search and Seizure §5.2(b), p. 132, and n. 15 (5th ed.
`2012).
`Although the existence of the exception for such searches
`
`
`has been recognized for a century, its scope has been de-
`bated for nearly as long. See Arizona v. Gant, 556 U. S.
`332, 350 (2009) (noting the exception’s “checkered his-
`tory”). That debate has focused on the extent to which
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`officers may search property found on or near the arrestee.
`
`Three related precedents set forth the rules governing
`such searches:
` The first, Chimel v. California, 395 U. S. 752 (1969), laid
`the groundwork for most of the existing search incident to
`arrest doctrine. Police officers in that case arrested
`Chimel inside his home and proceeded to search his entire
`three-bedroom house, including the attic and garage. In
`particular rooms, they also looked through the contents of
`drawers. Id., at 753–754.
`The Court crafted the following rule for assessing the
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`reasonableness of a search incident to arrest:
`
`“When an arrest is made, it is reasonable for the ar-
`resting officer to search the person arrested in order
`to remove any weapons that the latter might seek to
`use in order to resist arrest or effect his escape. Oth-
`erwise, the officer’s safety might well be endangered,
`and the arrest itself frustrated. In addition, it is en-
`tirely reasonable for the arresting officer to search for
`and seize any evidence on the arrestee’s person in or-
`der to prevent its concealment or destruction. . . .
`There is ample justification, therefore, for a search of
`the arrestee’s person and the area ‘within his immedi-
`ate control’—construing that phrase to mean the area
`from within which he might gain possession of a
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`Opinion of the Court
`weapon or destructible evidence.” Id., at 762–763.
`The extensive warrantless search of Chimel’s home did not
`fit within this exception, because it was not needed to
`protect officer safety or to preserve evidence. Id., at 763,
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`768.
`Four years later, in United States v. Robinson, 414 U. S.
`
`218 (1973), the Court applied the Chimel analysis in the
`context of a search of the arrestee’s person. A police of-
`ficer had arrested Robinson for driving with a revoked
`license. The officer conducted a patdown search and felt
`an object that he could not identify in Robinson’s coat
`pocket. He removed the object, which turned out to be a
`crumpled cigarette package, and opened it. Inside were 14
`capsules of heroin. Id., at 220, 223.
`The Court of Appeals concluded that the search was
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`unreasonable because Robinson was unlikely to have
`evidence of the crime of arrest on his person, and because
`it believed that extracting the cigarette package and open-
`ing it could not be justified as part of a protective search
`for weapons. This Court reversed, rejecting the notion
`that “case-by-case adjudication” was required to determine
`“whether or not there was present one of the reasons
`supporting the authority for a search of the person inci-
`dent to a lawful arrest.” Id., at 235. As the Court ex-
`plained, “[t]he authority to search the person incident to a
`lawful custodial arrest, while based upon the need to
`disarm and to discover evidence, does not depend on what
`a court may later decide was the probability in a particu-
`lar arrest situation that weapons or evidence would in fact
`be found upon the person of the suspect.” Ibid. Instead, a
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`“custodial arrest of a suspect based on probable cause is a
`reasonable intrusion under the Fourth Amendment; that
`intrusion being lawful, a search incident to the arrest
`requires no additional justification.” Ibid.
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`The Court thus concluded that the search of Robinson
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` RILEY v. CALIFORNIA
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`Opinion of the Court
`was reasonable even though there was no concern about
`the loss of evidence, and the arresting officer had no spe-
`cific concern that Robinson might be armed. Id., at 236.
`In doing so, the Court did not draw a line between a
`search of Robinson’s person and a further examination of
`the cigarette pack found during that search. It merely
`noted that, “[h]aving in the course of a lawful search come
`upon the crumpled package of cigarettes, [the officer] was
`
`entitled to inspect it.” Ibid. A few years later, the Court
`clarified that this exception was limited to “personal prop-
`erty . . . immediately associated with the person of the
`arrestee.” United States v. Chadwick, 433 U. S. 1, 15
`(1977) (200-pound, locked footlocker could not be searched
`incident to arrest), abrogated on other grounds by Califor-
`nia v. Acevedo, 500 U. S. 565 (1991).
`
`The search incident to arrest trilogy concludes with
`
`Gant, which analyzed searches of an arrestee’s vehicle.
`Gant, like Robinson, recognized that the Chimel concerns
`for officer safety and evidence preservation underlie the
`search incident to arrest exception. See 556 U. S., at 338.
`As a result, the Court concluded that Chimel could author-
`ize police to search a vehicle “only when the arrestee is
`unsecured and within reaching distance of the passenger
`
`compartment at the time of the search.” 556 U. S., at 343.
`Gant added, however, an independent exception for a
`
`warrantless search of a vehicle’s passenger compartment
`“when it is ‘reasonable to believe evidence relevant to the
`crime of arrest might be found in the vehicle.’” Ibid.
`(quoting Thornton v. United States, 541 U. S. 615, 632
`(2004) (SCALIA, J., concurring in judgment)). That excep-
`
`tion stems not from Chimel, the Court explained, but from
`“circumstances unique to the vehicle context.” 556 U. S.,
`at 343.
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`III
`
`These cases require us to decide how the search incident
`
`
`
`
`
`
`

`
`
`
` Cite as: 573 U. S. ____ (2014)
`
`Opinion of the Court
`to arrest doctrine applies to modern cell phones, which are
`now such a pervasive and insistent part of daily life that
`the proverbial visitor from Mars might conclude they were
`an important feature of human anatomy. A smart phone
`of the sort taken from Riley was unheard of ten years ago;
`a significant majority of American adults now own such
`phones. See A. Smith, Pew Research Center, Smartphone
`Ownership—2013 Update (June 5, 2013). Even less so-
`phisticated phones like Wurie’s, which have already faded
`in popularity since Wurie was arrested in 2007, have been
`around for less than 15 years. Both phones are based on
`technology nearly inconceivable just a few decades ago,
`when Chimel and Robinson were decided.
`Absent more precise guidance from the founding era, we
`
`generally determine whether to exempt a given type of
`search from the warrant requirement “by assessing, on the
`one hand, the degree to which it intrudes upon an individ-
`ual’s privacy and, on the other, the degree to which it is
`needed for the promotion of legitimate governmental
`interests.” Wyoming v. Houghton, 526 U. S. 295, 300
`(1999). Such a balancing of interests supported the search
`incident to arrest exception in Robinson, and a mechanical
`application of Robinson might well support the warrant-
`less searches at issue here.
` But while Robinson’s categorical rule strikes the appro-
` priate balance in the context of physical objects, neither of
`
`its rationales has much force with respect to digital con-
`tent on cell phones. On the government interest side,
`Robinson concluded that the two risks identified in
`
`
`Chimel—harm to officers and destruction of evidence—are
`
`
`present in all custodial arrests. There are no comparable
`risks when the search is of digital data. In addition, Rob-
`inson regarded any privacy interests retained by an indi-
`vidual after arrest as significantly diminished by the fact
`of the arrest itself. Cell phones, however, place vast quan-
`tities of personal information literally in the hands of
`
`
`
`
`
`9
`
`
`
`
`
`

`
`
`
`
`
`10
`
`
` RILEY v. CALIFORNIA
`
`Opinion of the Court
`individuals. A search of the information on a cell phone
`
`bears little resemblance to the type of brief physical search
`considered in Robinson.
`
`We therefore decline to extend Robinson to searches of
`data on cell phones, and hold instead that officers must
`generally secure a warrant before conducting such a
`search.
`
`A
`
`We first consider each Chimel concern in turn. In doing
`
`
`
`so, we do not overlook Robinson’s admonition that searches
`of a person incident to arrest, “while based upon the
`need to disarm and to discover evidence,” are reasonable
`regardless of “the probability in a particular arrest situa-
`tion that weapons or evidence would in fact be found.” 414
`U. S., at 235. Rather than requiring the “case-by-case
`adjudication” that Robinson rejected, ibid., we ask instead
`whether application of the search incident to arrest doc-
`trine to this particular category of effects would “untether
`the rule from the justifications underlying the Chimel
`exception,” Gant, supra, at 343. See also Knowles v. Iowa,
`525 U. S. 113, 119 (1998) (declining to extend Robinson to
`the issuance of citations, “a situation where the concern
`for officer safety is not present to the same extent and the
`concern for destruction or loss of evidence is not present at
`all”).
`
`
`
`1
`
`
`Digital data stored on a cell phone cannot itself be used
`
`
`as a weapon to harm an arresting officer or to effectuate
`the arrestee’s escape. 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. Once an officer has secured a phone and
`eliminated any potential physical threats, however, data
`
`
`
`
`
`

`
`
`
` Cite as: 573 U. S. ____ (2014)
`
`Opinion of the Court
`
` on the phone can endanger no one.
`Perhaps the same might have been said of the cigarette
`
`pack seized from Robinson’s pocket. Once an officer
`gained control of the pack, it was unlikely that Robinson
`could have accessed the pack’s contents. But unknown
`physical objects may always pose risks, no matter how
`slight, during the tense atmosphere of a custodial arrest.
`The officer in Robinson testified that he could not identify
`the objects in the cigarette pack but knew they were not
`cigarettes. See 414 U. S., at 223, 236, n. 7. Given that, a
`further search was a reasonable protective measure. No
`such unknowns exist with respect to digital data. As the
`First Circuit explained, the officers who searched Wurie’s
`cell phone “knew exactly what they would find therein:
`data. They also knew that the data could not harm them.”
`728 F. 3d, at 10.
`The United States and California both suggest that a
`
`search of cell phone data might help ensure officer safety
`in more indirect ways, for example by alerting officers that
`confederates of the arrestee are headed to the scene.
`There is undoubtedly a strong government interest in
`warning officers about such possibilities, but neither the
`United States nor California offers evidence to suggest
`that their concerns are based on actual experience. The
`proposed consideration would also represent a broadening
`of Chimel’s concern that an arrestee himself might grab a
`weapon and use it against an officer “to resist arrest or
`effect his escape.” 395 U. S., at 763. And any such threats
`from outside the arrest scene do not “lurk[ ] in all custodial
`arrests.” Chadwick, 433 U. S., at 14–15. Accordingly, the
`interest in protecting officer safety does not justify dis-
`pensing with the warrant requirement across the board.
`To