One of the larger Fourth Amendment issues of federal criminal law has been the warrantless search of cellphones. The Fifth Circuit decided United States v. Finley in 2007, which analogized cell phones to containers and held that police could indiscriminately search them without the need for a warrant. This ruling allowed provided law enforcement the incentive to detain people for small infractions such as traffic violations, and search their cell phones for evidence of more serious crimes. (We've represented several people over the years where this happened.)
Now all that has changed. This morning the Supreme Court handed down its unanimous decisions in Riley v. California and United States v. Wurie. In them it addressed the common question of whether police may search, without a warrant, a cell phone seized from an individual who has been arrested. The Court's answer is no.
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.
This decision marks a watershed in constitutional law and law enforcement investigation.
Read the opinion here.