Schneckloth v. Bustamonte

It is well settled under the Fourth and Fourteenth Amendments that a search conducted without a warrant issued upon probable cause is " per se unreasonable . . . subject only to a few specifically established and well-delineated exceptions." Katz v. United States, 389 U.S. 347, 357; Coolidge v. New Hampshire, 403 U.S. 443, 454-455; Chambers v. Maroney, 399 U.S. 42, 51. It is equally well settled that one of the specifically established exceptions to the requirements of both a warrant and probable cause is a search that is conducted pursuant to consent. Davis v. United States, 328 U.S. 582, 593-594; Zap v. United States, 328 U.S. 624, 630. The constitutional question in the present case concerns the definition of "consent" in this Fourth and Fourteenth Amendment context.