Two men robbed a gas station. The police obtained reliable information concerning the suspects, and when a blue station wagon was pulled over, the police had probable cause to believe that the men in the car were responsible for the robbery. The four men in the car were arrested, and the car was brought back to the police station, where it was searched. In the car the police found two guns, money, and other evidence linking one of the car’s occupants, Chambers (defendant), with both the robbery of the gas station and also another robbery that had occurred a few days earlier. The evidence found in the car was introduced at trial, and Chambers was convicted of both robberies. Chambers did not directly appeal his convictions, but he filed a habeas corpus petition that was denied in the state courts. Chambers subsequently filed a habeas corpus petition in federal court; the district court denied his petition, and the appellate court affirmed. The United States Supreme Court granted certiorari.