Pennsylvania v. Mimms

A routine expired-plate stop became a major Fourth Amendment rule. In Pennsylvania v. Mimms, officers lawfully stopped Harry Mimms, asked him to step out of the car, saw a bulge under his jacket, and found a loaded revolver during a frisk.

The Supreme Court held that asking the driver to exit a lawfully stopped vehicle is only a minimal additional intrusion and is justified by officer safety. The frisk was separately supported by the officer seeing a bulge that could reasonably indicate a weapon.

The key rule is narrow: Mimms supports the exit order during a lawful traffic stop, but it does not make every frisk or search automatic. Officers still need a safety basis for a pat-down.