Summary
Carroll v. United States, 267 U.S. 132 (1925), upheld a warrantless search of an automobile during Prohibition because officers had probable cause to believe it carried illegal liquor. The decision established the automobile exception: mobility can make a warrant impractical, but probable cause remains required.
Legal Issue
Does the Fourth Amendment permit officers to stop and search an automobile without a warrant when they have probable cause to believe it contains contraband that can be quickly moved away?
Holding
Yes. The Court held that a warrantless automobile search is reasonable under the Fourth Amendment when officers have probable cause to believe the vehicle contains contraband, because vehicles are mobile and differ from homes or fixed buildings where warrants can more readily be obtained.
Rule of Law
A car is not treated like a house for Fourth Amendment purposes. If officers have real probable cause that a vehicle contains contraband, they may search it without first getting a warrant.
Court Reasoning
Not yet summarized.
Impact for Officers
Modern courts still cite Carroll when evaluating vehicle searches, though later cases refine scope, containers, consent, inventory searches, and how probable cause applies in traffic-stop settings.
What Officers Can Do
Not yet summarized.
What Officers Should Avoid
Not yet summarized.
Common Misunderstanding
Not yet summarized.