Arizona v. Johnson, 555 U.S. 323 (2009), is a United States Supreme Court case in which the Court held, by unanimous decision, that police may conduct a pat down search of a passenger in an automobile that has been lawfully stopped for a minor traffic violation, provided the police reasonably suspect the passenger is armed and dangerous.

[1][2] Tucson, Arizona, police officers were patrolling a neighborhood associated with the Crips street gang when they stopped a vehicle because its registration had been suspended.

Officers noticed that Lemon Montrea Johnson, the vehicle's backseat passenger, looked back and kept his eyes on the officers as they approached, that he was wearing a blue bandana (consistent with Crips membership), and that he had a police scanner in his pocket.

While in the car, Johnson stated that he was from a town the officer knew to be associated with the Crips gang, and also admitted that had served a prison sentence for burglary and had been out for about a year.

The police were not required to give Johnson the opportunity to leave without ensuring that he was not armed and dangerous.