What does Michigan v. Long allow for law enforcement during a vehicle stop?

Michigan v. Long established the principle that law enforcement officers may conduct a limited search of a vehicle for weapons during a lawful stop if they have a reasonable belief that the occupants may be armed and dangerous. This decision arose from concerns about officer safety during traffic stops, where officers might not know whether a suspect possesses a weapon that could pose a threat.

In this case, the Supreme Court held that when an officer conducts a traffic stop and has a specific and articulable basis for concern about the presence of a weapon, they are justified in searching the passenger compartment of the vehicle, including any containers within that area, for the purpose of ensuring their safety. This is often referred to as a "Terry stop" for vehicles, allowing for a pat-down search but not a full search of the entire vehicle or its contents without specific probable cause.

This ruling promotes the balance between the need for police officers to ensure their safety during encounters and the individuals' rights against unreasonable searches and seizures, under the Fourth Amendment.