ABSTRACT
The Fourth Amendment imposes two requirements for searches and seizures, in general, to be valid: a search warrant and probable cause. The rule is different, however, in vehicular stops and searches, because motor vehicles are mobile and can be driven away at any time, making obtaining a warrant impractical. This rule was laid out in Carroll v. United States, 267 U.S. 132 (1925), in which the Supreme Court held that the search of an automobile without a warrant is valid as long as probable cause is present.
