On June 25, 2014, the Supreme Court of the United States decided Riley v. California, No. 13-132, and United States v. Wurie, No. 13-212, holding that police must generally obtain a warrant before searching a cell phone seized incident to a lawful arrest.
In one opinion, the Court considered two cases, both of which involved warrantless police searches of cell phones seized incident to lawful arrests. In the first, California police lawfully arrested David Riley for possession of concealed and loaded firearms discovered when the police lawfully performed an inventory search of his car after pulling him over and discovering that he was driving on a suspended license. An officer also searched a smart phone seized incident to Riley's arrest and discovered text messages and videos suggesting that Riley had been involved in a shooting a few weeks earlier. Riley was ultimately charged with firing at an unoccupied vehicle, assault with a semiautomatic weapon, and attempted murder.
In the second case, an officer performing routine surveillance observed Brima Wurie make an apparent drug sale from a car. Officers arrested Wurie and seized a flip phone incident to the arrest. After noticing that the phone was repeatedly receiving calls from a number identified on the phone as "my house," they opened the phone and used an online phone directory to trace that number to an apartment building. When officers went to the building, they found Wurie's name on a mailbox and observed through a window a woman who resembled a picture on the phone. After securing a warrant to search the premises, officers discovered 215 grams of crack cocaine, a firearm, cash, and other drug paraphernalia. The United States ultimately charged Wurie with distributing crack cocaine and being a felon in possession of a firearm and ammunition.
Both Riley and Wuria moved to suppress evidence obtained following the searches of their cell phones, on the grounds that it was fruit of an unconstitutional search. Both trial courts denied the motions, and in Riley's case, the California Court of Appeal affirmed. In Wurie's case, a divided panel of the United States Court of Appeals for the First Circuit reversed the denial of the motion to suppress and vacated Wurie's conviction. The Supreme Court granted certiorari in both cases.
The Supreme Court unanimously held that, as a general matter, police must obtain a warrant to search a cell phone seized incident to a lawful arrest. In doing so, the Court discussed at length how the Fourth Amendment's protection against unreasonable searches and seizures applies to digital data stored in cell phones seized incident to a lawful arrest.
Absent precise guidance from the founding era, the Court applied a balancing test—taken from its precedents—to determine whether a warrant should be required to search cell phones seized incident to a lawful arrest: it assessed, on one hand, the degree to which searching a cell phone "intrudes upon an individual's privacy" and, on the other, the "degree to which it is needed for the promotion of legitimate governmental interests." Since the search-incident-to-arrest exception focused on two such interests—ensuring officer safety and preventing destruction of evidence—the Court first analyzed the extent to which searches of cell phones either ensure officer safety or prevent the destruction of evidence.
The Court concluded that searching a cell phone incident to an arrest did not seriously implicate either concern. This is because 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." Likewise, once officers have secured a cell phone, there is "no longer any risk that the arrestee himself will be able to delete any incriminating data from the phone." The Court rejected the governments' expressed concerns about remote wiping and data encryption, both because there was "little reason to believe either problem is prevalent" and because there are other means with which law enforcement can address concerns about remote wiping or data encryption, such as simply turning off the phone or using a so-called "Faraday bag" to isolate it from radio waves.
As to the interest in individual privacy, the Court concluded that, unlike physical objects seized incident to lawful arrests that contain limited amounts of information (like wallets, purses, and the like), digital data stored on cell phones may include vast amounts of information, akin to the combination of cameras, video players, rolodexes, calendars, tape recorders, diaries, albums, maps, and newspapers. Thus, from a pure quantitative perspective, a search of a cell phone would effectively permit the search of "the sum of an individual's private life," going back to a time even before the phone was purchased. From a qualitative perspective, the Court stressed how modern cell phones contain "detailed information about all aspects of a person's life," including about the person's familial, political, professional, religious, and sexual associations. Because the privacy interests "dwarf[ed]" those in prior cases, the Court rejected the governments' attempt to analogize searches of digital data to searches of physical items. In stark terms, the Court explained that such an analogy was "like saying a ride on horseback is materially indistinguishable from a flight to the moon."
Finally, the Court rejected the governments' attempts to permit case- or context-specific searches of cell phones seized incident to a lawful arrest, both because such searches were unworkable and because police need clear rules to govern their behavior. The Court emphasized that other tools, including the exception to the warrant requirement for exigent circumstances, would prevent some of the governments' expressed concerns. The Court concluded: "Our answer to the question of what police must do before searching a cell phone seized incident to an arrest is accordingly simple: get a warrant."
Chief Justice Roberts delivered the opinion for a unanimous Court. Justice Alito delivered an opinion concurring in part and concurring in the judgment.