On December 10, 1973, police in Vermillion, South Dakota ticketed and then towed an illegally parked car. At the impound lot, the officer saw a watch and other property inside the car. The officer had the car door unlocked and performed a routine inventory search, using a standard inventory form. The officer found drugs in the unlocked glove compartment. The drugs and other items were removed from the car. Opperman (defendant) was arrested for marihuana possession when he arrived at the police department to claim his property. Opperman’s motion to suppress evidence found in the inventory search was denied. Opperman was tried by a jury, convicted, and sentenced to a $100 fine and two weeks in county jail. The Supreme Court of South Dakota reversed Opperman’s conviction and held that the police violated the Fourth Amendment. The United States Supreme Court granted certiorari.