In addition to their law-enforcement duties, the police must engage in what the court has termed a community caretaking role, including the removal of obstructions from roadways to ensure the free flow of traffic.

Arriving at the garage, Weiss opened the Thunderbird's door, finding a Chicago police regulations book on the floor and a flashlight "with a few spots of blood" between the two front seats.

Discovering a pillowcase, briefcase, and the back seat covered in blood, deputies obtained search warrants to fully examine both the Thunderbird and the Dodge.

However, the United States Court of Appeals for the Seventh Circuit reversed his conviction on the basis that the socks and floor mat were improperly seized.

[2] In a 5–4 decision, Justice William Rehnquist wrote for the majority that since state and local law enforcement agencies engage with vehicles more frequently than federal agents, the former take a "community caretaker" role of ensuring safe travels on public roads.

[3] Even as the majority of vehicle accidents are of a non-criminal nature, the frequent response from local police brings evidence and contraband into plain view.

Differentiating from Preston v. United States (1964)[4] where the Court upheld the suppression of bank robbery conspiracy evidence (as the defendants were initially arrested for vagrancy), the search of the Thunderbird was justified under procedure.

Finally, the Dodge was a "particularly described" item in the Fond du Lac Sheriff's search warrant; thus the sock and mat could be seized under plain view.

Justice William Brennan dissented, arguing that the search was not justifiable without a warrant as the vehicle was not forfeited and the officers removed it from the highway.