Do police need a warrant to search a cellphone?

On Tuesday the U.S. Supreme Court listened to arguments in two cases disputing whether the Constitution protects citizens’ cellphones from being searched during an arrest. Lower courts have issued split decisions about whether police need a warrant to search a suspect’s cellphone.

The question brings the Bill of Rights squarely into the digital age: The Fourth Amendment protects Americans from “unreasonable searches and seizures” of their “persons, houses, papers, and effects.” Some lawyers argue the content of smartphones qualifies as personal “papers and effects.” The Obama administration, on the other hand, argues police should be able to search a phone during an arrest—an action that could reveal texts, phone numbers, photos, or location information tying the suspect to a crime.

Courts have already ruled police may take wallets, weapons, papers, cigarettes, and other items found on a person’s body during an arrest. But those items contain far less personal information than might be stored on a smartphone in a suspect’s pocket.

On Tuesday, the justices seemed skeptical of taking an all-or-nothing approach of either allowing warrantless cellphone searches or prohibiting them. If allowed, police might be able to search a phone for private information during a traffic arrest. If prohibited, it might be difficult for police applying for a search warrant to describe to a magistrate exactly what they expect to find on a phone.

The first case before the justices, Riley v. California, involved a college student, David Riley, arrested in San Diego in 2009 for driving with an expired license plate and a suspended license. Police found firearms under the hood of Riley’s Lexus, and searched his phone twice, finding a picture of Riley posing with a gang member. They did not have search warrants.

Partly because of the evidence found on the phone, Riley was later convicted of armed assault and attempted murder. He appealed the conviction, but a California appeals court ruled the police search of Riley’s cellphone was legal even without a warrant. The California Supreme Court has ruled that such searches are little different than checking an arrestee’s pockets for personal belongings.

On Tuesday, Justice Samuel Alito seemed skeptical that photos stored on a cellphone were any different from photos tucked in a wallet.

“Suppose your client were an old school guy and he didn’t have a cellphone,” Alito asked Jeffrey Fisher, the lawyer representing Riley. “He had a billfold and he had photos that were important to him in the billfold. He had that at the time of arrest. Do you dispute the proposition that the police could examine the photos in his billfold and use those as evidence against him?”

“No,” replied Fisher. “The difference is digital information versus physical items,” which can sometimes pose a safety threat, he claimed.

Chief Justice John Roberts pointed out that some smartphone apps, like those for Facebook or Twitter, often contain information that is expected to be publicly posted. Fisher conceded phones might contain a “sliding scale” of information intended to be either public or private, but argued content on a smartphone is “intertwined” with other types of data, like GPS data, that have an expectation of privacy.

Demonstrating some knowledge of the latest personal gadgets, Roberts asked whether Fisher thought police without a warrant could digitally search a Fitbit, a device that tracks movement and activities like walking or running, worn a suspect’s wrist. “The defendant says, ‘I’ve been in my house all afternoon.’ And they want to check and see if he’s walked 4 miles. … Is that something they can look at?”

“I think probably not,” Fisher said.

Edward DuMont, the lawyer representing California, argued that just as police are permitted to look through photos in a person’s wallet, they should be able to look at the same photos, in digital form, on a phone.

But Justice Elena Kagan pointed out that a person being arrested for something as simple as driving without a seatbelt could have his personal and work emails, intimate communications, medical records, bank records, calendar, and location data revealed by a cellphone search. “That strikes me as a very different kind of world than the kind of world that you were describing, where somebody has pictures of their family in a billfold.”

DuMont said police should be allowed to search any devices—including not just smartphones but computers and iPads—“on the person or immediately associated with [the person]—for instance, in a purse,” at the time of an arrest. But that wouldn’t necessarily include devices lying nearby.

“Suppose I’m carrying my laptop in my backpack,” Kagan asked.

“Yes, we think that’s included,” DuMont said.

The second case before the Supreme Court, U.S. v. Wurie, involved the more limited content of a flip phone. In 2007, police scrolled through a flip phone belonging to Brima Wurie, arrested in Boston for selling crack cocaine. They found a phone number that led them to a house where Wurie had been keeping drugs, a gun, and ammunition. Wurie was later convicted of crimes involving drugs and weapons, but a federal appeals court threw out the evidence gathered from the flip phone, saying the warrantless search was illegal.

The justices could overturn the appeals court’s decision if they determine that looking through call logs does not require a warrant. On Tuesday, they hinted they could rule in a way that would allow police to search a phone if they had reason to believe it contained evidence for a specific crime but not in the case of an arrest for a petty offense.

The court should issue a decision by June.