The Federal and Massachusetts Constitutions typically prohibit police officers from searching private locations without first obtaining a warrant. The warrant requirement, however, does not generally apply to automobiles. The United States Supreme Court and the Massachusetts Supreme Judicial Court have ruled that when the police have probable cause to believe contraband or evidence of a crime will be found in a car that is in a public place, they may search the car without a warrant. These warrantless searches are justified for two reasons. First, motor vehicles are inherently mobile. Therefore, if the police were forced to wait for a warrant to search, there would be a substantial risk that the evidence or contraband would be moved. Second, we all have a reduced expectation of privacy in the items we keep in our cars (as opposed to items we keep in our homes or offices, for example) because our cars are subject to considerable governmental regulations.
Limited Scope of Search Pursuant to the Automobile Exception
Under the automobile exception, the police may search a car only if there is probable cause to believe contraband or evidence of a crime will be discovered. Therefore, the police must generally know the types of objects that are the subject of the search, and officers may only search those areas of the car that could conceivably hold the evidence or the contraband. For example, if the cops have probable cause to believe there is a gun in a car, they can search the passenger compartment, under the seats, and inside the glove compartment, since the gun could be hidden in any of those places. If the police find a prescription pill bottle inside of the car, the officers cannot open the bottle under the automobile exception because there is no possibility that a gun could be located therein.