Read on to find out how this critical law can make a difference in your criminal case. Vehicles can be searched without a warrant if police have probable cause to believe the vehicle contains evidence of a crime.Exigent circumstances; Plain view; Search incident to arrest; Consent; Automobile exceptions; Special needs. The Fourth Amendment's rule against unreasonable search and seizures means that police may not search you or your property unless one of the following is true:. "For the Second Extended Term, CITY accepts the Premises in its "As-. The Fourth Amendment, however, is not a guarantee against all searches and seizures, but only those that are deemed unreasonable under the law. Honest mistake of the police. The Fourth Amendment warrant requirement is subject to certain exceptions. The Fourth Amendment generally requires police to obtain a warrant before conducting a search. The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated.