Are police allowed to rummage through the contents of a cell phone when a person is arrested? The U.S. Supreme Court is currently deciding whether to grant review in two cases involving the thorny issue. Together with the Center for Democracy and Technology, we've filed an amicus brief with the Supreme Court asking it to grant review in Riley v. California, a case involving the warrantless search of a smartphone incident to arrest.

The Fourth Amendment requires the police to get a warrant before conducting a search. But the Supreme Court has permitted police to search a person and the areas and items within the arrestee's immediate control upon arrest without a warrant. This exception to the warrant requirement has been justified for two reasons: first, protecting officer safety means searching the person to ensure they aren't carrying a weapon; and second, a warrantless search is justified by the need to ensure no evidence is lost or destroyed.

But this doctrine was developed by the Supreme Court in an age before cell phones. While courts have permitted the warrantless search of things like clothes or cigarette packs on a person under the exception, a modern smartphone is a far different thing, capable of storing immense amounts of information. As warrantless cell phone searches incident to arrest have become more widespread, state and federal courts reviewing the constitutionality of these searches have reached conflicting opinions. But as cell phones have evolved to become miniature computers, courts looking at the issue are hesitating to provide officers with wide searching authority. The two most recent court decisions on the issue, from the Florida Supreme Court in Smallwood v. State and the federal First Circuit Court of Appeals in United States v. Wurie, ruled such searches were not permitted especially because of the massive amounts of information stored on a smartphone.

Wurie involved a simple flip phone that did not have Internet capabilities. After the federal government lost Wurie, it asked the U.S. Supreme Court to review the case. At the same time, a petition for certiorari was filed in Riley, a case from California that upheld the warrantless search of a smartphone incident to arrest. With the Supreme Court now deciding whether to review one or both of these cases, our amicus brief argues that the court should grant review of the case involving a smartphone, as whether the warrantless search is valid or not depends in large part on the fact phones carry far more information than physical items the court has previously considered. And at a time when the majority of American adults are carrying smartphones, deciding a case involving the technology currently in use will give courts, officers, and the public clear guidance of what type of search is permitted incident to arrest. Even the justices themselves have recognized they will have to confront these difficult questions regarding law enforcement encroachment into sensitive information and emerging technologies. We hope the court will grant review in a case involving a widely used smartphone rather than a more primitive technology fading from public.

The brief was authored by Andrew Pincus of Mayer Brown LLP and the Yale Law School Supreme Court Clinic.