What Does the Fourth Amendment Mean? The 4th amendment prohibits unreasonable search and seizure.There is no general exception to the Fourth Amendment warrant requirement in national security cases. As framed in the Carroll opinion, the automobile exception provides that an officer does not need a warrant to stop and search a car provided. Addressed in the OPD "Warrants - Search Warrant Service" policy. A police officer must fill out an affidavit and present it to a neutral judge or magistrate to obtain a warrant. Law enforcement officials must have probable cause to get a search warrant, and a judge must agree that the warrant is necessary to the case. Where a person is a third party in a location where a search or seizure takes place (e.g. Where a person is a third party in a location where a search or seizure takes place (e.g. Ventresca, 380 U.S. 102, 106 (1965) ("in a doubtful or marginal case a search under a warrant may be sustainable where without one it would fall"); Beck v.