It is well-settled that the fourth amendment allows for warrantless arrests outside the home as long as the police have probable cause to arrest the suspect. 2d 838 (2001) The central requirement of the Fourth Amendment is that police act reasonably.Police must have a warrant to search a person or vehicle unless they already have probable cause that it contains contraband or evidence of a crime. If the police violate the Fourth Amendment, evidence they obtained during an unlawful search might be excluded in court. If the officer does not have probable cause to arrest you, any items found in a search incident to arrest must be suppressed due a Fourth Amendment violation. The Fourth Amendment generally requires government officials to obtain an arrest warrant or search warrant to execute a valid search and seizure. A police officer must fill out an affidavit and present it to a neutral judge or magistrate to obtain a warrant. In the discretion of police officers. Requirement of the Fourth Amendment."1. California, 551 U.S. __, 127 S. Ct. 2400 (2007).