Terry v. Ohio, 392 U.S. 1 (1968) (U.S. Supreme Court)
Terry v. Ohio is the foundational Fourth Amendment case that created the modern framework for "stop and frisk." Before Terry, constitutional doctrine largely treated police–citizen encounters as either consensual or full-scale arrests requiring probable cause.
Does the Fourth Amendment permit a police officer to stop a person for investigation and conduct a limited patdown for weapons, absent probable cause to arrest, when the officer has reasonable suspicion that criminal activity is afoot and that the person may be armed and dangerous?
The Fourth Amendment's prohibition on unreasonable searches and seizures applies to brief investigatory detentions and to limited protective frisks. An officer may (1) stop an individual if the officer can point to specific and articulable facts, together with rational inferences from those facts, that reasonably warrant the intrusion—i.e., reasonable suspicion that the person is engaged in, has engaged in, or is about to engage in criminal activity; and (2) conduct a carefully limited patdown of the outer clothing for weapons if the officer reasonably believes the person is armed and presently dangerous. The encounter must be justified at its inception and reasonably related in scope to the circumstances that justified the stop, with the frisk confined to what is necessary to discover weapons.
Yes. The stop of Terry and the limited frisk for weapons were reasonable under the Fourth Amendment, even though the officer lacked probable cause to arrest. The weapons were admissible because the officer had reasonable suspicion based on specific observations and confined his search to a protective patdown for weapons.
Terry created the doctrinal framework for the investigatory stop and protective frisk, introducing the reasonable suspicion standard and the two-part test (justification and scope). It is the cornerstone of modern street-level policing and later cases involving traffic stops, officer-safety frisks, and the permissible scope of searches during temporary detentions. For law students, Terry is essential because it: (1) defines reasonable suspicion and distinguishes it from probable cause; (2) illustrates the Court's interest-balancing approach to Fourth Amendment reasonableness; (3) sets limits on the scope and purpose of frisks; and (4) serves as a platform for understanding subsequent developments (e.g., traffic-stop frisks, anonymous tips, high-crime area considerations, and the plain-feel doctrine).