What part of a motor vehicle can be searched incident to arrest?

The passenger compartment can be searched incident to an arrest because it is considered an area within the immediate control of the arrestee at the time of their arrest. This principle is grounded in the legal doctrine that allows law enforcement officers to ensure their safety and preserve evidence when they have made a lawful arrest inside a vehicle. The passenger compartment specifically includes areas where an arrestee could reach for weapons or evidence.

In contrast, the trunk of the vehicle generally requires a separate basis for search, such as probable cause, as it is not readily accessible to the arrestee during the arrest process. The back seat area may be part of the passenger compartment but is considered along with the overall control of the area. All locked compartments typically fall outside the scope of a search incident to arrest without additional justification, as they do not allow immediate access and would require a warrant or probable cause for a legal search.