In a 5-4 decision, the justices set aside a 1981 opinion that had given police broad authority to search cars whenever they made an arrest.
Justice John Paul Stevens, speaking for the court, said that merely arresting a driver does not “provide a police entitlement” to search the vehicle without a warrant.
He said the court’s past rulings had given police too much leeway, allowing them to search cars even when there was no threat to officers’ safety. For example, if a motorist was handcuffed and put in a patrol car, there was no danger that he could reach a weapon in his car.
The lineup behind Stevens was unusual. Justices Antonin Scalia, David H. Souter, Clarence Thomas and Ruth Bader Ginsburg formed the majority.
The case arose when Rodney Gant was arrested in Tucson for driving with a suspended license. His car was parked in his driveway, and officers handcuffed Gant and put him in a patrol car. Then they searched the car and found a gun and cocaine in a jacket in the back seat.
Gant was convicted on drug charges, but the Arizona Supreme Court threw out evidence on the grounds that the search of his car without a warrant was unreasonable.
The U.S. Supreme Court affirmed that decision Tuesday in Arizona vs. Gant.
The dissenters, led by Justice Samuel A. Alito Jr., said the court should have stuck with the old rule that permitted vehicle searches whenever a driver or an occupant was arrested.