In Terry v. Ohio (1968), the U.S. Supreme Court addressed the circumstances under which a police officer may stop and question a suspect, without the suspect's consent, in the absence of probable cause for arrest. Under the "Terry" ruling, investigative stops or detentions may only be conducted when an officer has an objective reasonable suspicion, based on the officer's experience, that criminal activity may be underway or imminent. The protective frisk of a suspect's outer clothing may be conducted only when the officer has additional specific and articulable facts from which it can be reasonably inferred that the suspect is armed and presently dangerous. The frisk must be limited in scope and designed to discover only hidden weapons. The facts upon which such a search is based must be objective and not grounded in speculation or the officer's subjective feelings. The 23 court cases reviewed pertain to investigative detentions of persons, vehicles, and property.