This morning the United States Supreme Court ruled in two cases that cell phone searches require a warrant.

The first case, Riley v. California, No. 13-132, arose from the arrest of David L. Riley, who was pulled over in San Diego in 2009 for having an expired auto registration. The police found loaded guns in his car and, on inspecting Mr. Riley’s cellphone, found entries they associated with a street gang.

A more comprehensive search of the phone led to information that linked Mr. Riley to a shooting. Riley was later convicted of attempted murder and sentenced to 15 years to life in prison. A California appeals court said neither search had required a warrant.

The second case, United States v. Wurie, No. 13-212, involved a search of the call log of the flip phone of Brima Wurie, who was arrested in 2007 in Boston and charged with gun and drug crimes. The federal appeals court in Boston last year threw out the evidence found on Mr. Wurie’s phone.

Chief Justice John G. Roberts, Jr. delivered the opinion of the Court in both Riley v. California, No.13-132, and United States v. Wurie, No. 13-212. Justice Alito issued an opinion concurring in part and concurring in the judgment.

You can access the oral arguments here and here, respectively.