In 1968, the Supreme Court decided Terry v. Ohio, a case that changed how police officers can interact with people on the street. The ruling created the legal basis for what is known as “stop-and-frisk.”

The case began when a Cleveland police officer saw three men walking back and forth in front of a store and looking inside. The officer believed they might be planning a robbery. He approached them and performed a quick pat-down of their outer clothing. During the frisk, he found a gun on John Terry and arrested him.

Terry argued that the search violated the Fourth Amendment, which protects people from unreasonable searches and seizures. Normally, police need “probable cause” to search someone. The key question was whether an officer could stop and frisk someone without probable cause.

In an 8–1 decision, the Supreme Court ruled that police can stop a person if they have “reasonable suspicion” that the person is involved in criminal activity. If the officer reasonably believes the person may be armed and dangerous, they can also perform a limited pat-down for weapons. However, the search must be brief and only for safety, not to gather evidence. This decision created a new legal standard called “reasonable suspicion,” which is lower than probable cause but must be based on specific facts, not just a guess.

Terry v. Ohio has had a major impact on policing in the United States. While some believe it helps prevent crime and protect officers, others argue it has led to unfair targeting of certain communities. The case remains an important part of constitutional law today.