The authority of the police, under certain circumstances, to approach and conduct an investigatory detention of a citizen and a limited search for weapons.

The Fourth Amendment prohibits unreasonable search and seizureSearch and seizure by the police without a warrant. The Uniform Arrest Act of 1942 and some state statutes, including a New York law, allowed police officers to briefly detain a person for questioning if they suspected illegal activity and frisk them (run their hands over the outside of the suspect’s clothing) in search of a weapon.

In Terry v. Ohio[case]Terry v. Ohio[Terry v. Ohio] (1968), the Supreme Court held that police officers can stop a person briefly for the purpose of investigation if they have a reasonable, articulable suspicion that criminal activity is occurring. The Court did not define the term “reasonable suspicion” but placed it somewhere between a vague suspicion and probable cause. The duration of the stop and frisk is limited to the amount of time necessary to either confirm or eliminate the officer’s suspicions about the suspect. The Court also stated that an officer may conduct a limited search or “pat down” of the suspect to ensure their safety and that of the public if they have reason to believe the suspect is armed and dangerous.

Fourth Amendment

Maryland v. Buie

Search warrant requirement

Terry v. Ohio