A search warrant is a document allowing the police to conduct a search. The search warrant must be signed by a judge and allows a search in a certain place and for certain items. Probable cause must be established. If a search is conducted without a warrant, it will be considered unreasonable unless the police are able to show an exception to the requirement was justified. The search must stay inside the scope of the warrant, including the locations searched or the items searched for. Exceptions to search without a warrant include valid consent by an occupant, evidence in plain view, and emergencies requiring prompt action.