Police officers must obtain a search warrant before scouring the contents of a suspect's cell phone unless their safety is in danger, a divided Ohio Supreme Court ruled Tuesday on an issue that appears never to have reached another state high court or the U.S. Supreme Court.

The Ohio high court ruled 5-4 in favor of Antwaun Smith, who was arrested on drug charges after he answered a cell phone call from a crack cocaine user acting as a police informant.

Officers took Smith's cell phone when he was arrested and, acting without a warrant and without his consent, searched it. They found a call history and stored numbers that showed Smith had previously been in contact with the drug user.