United States v. Robinson

United States v. Robinson was a 1973 decision by the United States Supreme Court that held that "in the case of a lawful custodial arrest, a full search of the person is not only an exception to the warrant requirement of the Fourth Amendment, but is also a reasonable search under that Amendment."

Background
A Washington Metro officer stopped a 1965 Cadillac based on reliable information that the driver's operating license had been revoked. All three occupants exited the car, and the officer arrested the driver, Robinson. (For purposes of the Court's opinion, it was assumed that Robinson's full-custody arrest was valid). The officer proceeded to search Robinson, and felt a package whose contents the officer could not immediately identify. Upon removing the package — a crumpled cigarette packet — and opening it, the officer discovered "14 gelatin capsules of white powder" that turned out to be heroin.