The concept of a Terry stop originated in the 1968
Supreme Court case
Terry v. Ohio, in which a police officer detained three
Cleveland men on the street behaving suspiciously, as if they were preparing for
armed robbery. The police conducted a pat down search and discovered a revolver, and subsequently, two of the men were convicted of
carrying a concealed weapon.
[7] The men appealed their case to the Supreme Court, arguing that the revolver was found during an illegal search under the
Fourth Amendment. This brief detention and search were deemed admissible by the court, judging that the officer had
reasonable suspicion which could be articulated (not just a hunch) that the person detained may be armed and dangerous. It is key to note that not just "mere" suspicion was used, but "reasonable" suspicion which could be articulated at a later date.
[8]