Although the Fourth Amendment requires that all searches and seizures be reasonable, usually necessitating a prior arrest or search warrant, the Supreme Court has recognized some exceptions, particularly where motor vehicles are concerned. Each exception has its own set of factual predicates that must be present, as well as limits on the scope of the search and seizure action. Pat-down searches of detained suspects can be carried out if the officer can reasonably suspect that the suspect is armed and dangerous. The officer may pat-down the suspect's outer clothing and may proceed to the inner clothing if there seems to be a concealed weapon there; the search can continue only to locate and remove the weapon. In a vehicular pat-down, the officer must have reasonable suspicion of a readily accessible deadly weapon in the vehicle; the examination must be limited to areas where such weapons could be concealed. An investigative detention must be justified by the officer as necessary for legitimate safety reasons or to complete logical investigative steps. A legal arrest requires that the officer has evidence of a crime and evidence that the detainee was the offender. Probable cause to arrest gives the officer much greater latitude in his actions; there is no limit on investigative detention, restraining devices may be used, and full searches are authorized. Officers may search the vehicle's passenger compartment as an incident to the occupant's arrest if the arrest is lawful, if the search is contemporaneous with the arrest, if the search is conducted before the car is moved, and if the search does not exceed its limitations. An extensive search of a vehicle located in a public place can be made if there is reasonable suspicion that criminal evidence or contraband is concealed, if the officer has legal access to the car's location, and if the search is limited to places where the evidence could reasonably be concealed. When a car is legally impounded, the officer may take inventory of its contents in order protect the property, locate hazardous items, and verify the contents. During searches legally conducted without warrants, the officer is authorized to seize items that he has probable cause to believe are evidence. 51 endnotes.