The Supreme Court defined the extent to which the federal rules covering searches and seizures should apply to the states.

California authorities entered the apartment of George and Diane Ker using a passkey and conducted a warrantless search during which they found and seized marijuana. In a 5-4 decision, the Supreme Court upheld their convictions, but the Court was divided about the facts of the case. Eight justices held that the state was required to adhere to federal standards, but a plurality of four, in an opinion written by Tom C. Clark,Clark, Tom C.;Ker v. California[Ker v. California] held that California had met those standards. Justice John M. Harlan II concurred in the result, but apparently was the only justice who thought that states should be held to a more flexible standard than the federal government. Chief Justice Earl Warren and Justices William J. Brennan, Jr., Arthur J. Goldberg, and William O. Douglas agreed that the states should be held to the same strict standards as the federal government when conducting searches and seizures but did not believe the actions of the California authorities should qualify under federal standards. The exclusionary rule applied in the Mapp v. Ohio[case]Mapp v. Ohio[Mapp v. Ohio] (1961) decision remained a weapon for use by the Court even after this decision.Search and seizure;Ker v. California[Ker v. California]

Due process, procedural

Exclusionary rule

Fourteenth Amendment

Fourth Amendment

Incorporation doctrine

Mapp v. Ohio

Search warrant requirement