The Fourth Amendment to the U.S. Constitution protects you from unreasonable searches and seizures. 1. The Fourth Amendment's rule against unreasonable searches and seizures mean the police cannot search you or your vehicle unless one of the following is true.Peace officers must demonstrate that probable cause exists to search a specific place for specific property or contraband which will be used as evidence. Probable Cause Exists to Search the Premises. The Fourth Amendment prohibits only "unreasonable searches and seizures. " The key word is "unreasonable. Gorak47 the court ruled that officers had probable cause to seize an air compressor in plain view in the back seat of the defendant's car mainly because "the. The Fourth Amendment generally requires police to obtain a warrant before conducting a search. The Fourth Amendment also requires that any arrest be based on probable cause, even when the arrest is made pursuant to an arrest warrant. The Fourth Amendment to the United States Constitution protects persons from unreasonable search and seizure.