Terry v. Ohio
Terry v. Ohio, 392 U.S. 1 (1968), was a landmark United States Supreme Court case regarding the authority of a police officer to detain a person if the officer had reasonable, articulable suspicion that criminal activity was afoot, and that a limited pat-down or frisk of the outer garments of the person was reasonable under the Fourth Amendment to the United States Constitution.
Facts of the case
On October 31, 1963, at about 2:30 p.m., Cleveland police detective Martin McFadden observed John W. Terry and Richard Chilton on a street corner. Officer McFadden's attention was drawn to the two men and he began to observe them. McFadden watched the two men, one at a time walk by a store window about a dozen times, then talk to a third man for a few minutes, until the third man walked away. Terry and Chilton continued to walk past the store window for another 10-12 minutes, after which they began to walk down the same street as the third man.
McFadden, based 39 years experience as a police officer and on the subjects actions believed that the were casing the store to commit a robbery. He also feared that the men may be armed. Following Terry and Chilton, McFadden saw them meet with the third man again. McFadden then contacted the men, identifying himself as a police officer and asking their names. When the men were not very responsive, McFadden grabbed Terry, spun him around and patted down Terry's outer clothing.
During the pat-down or frisk, McFadden felt a weapon and removed a .38 caliber revolver. He also found a revolver on Chilton, but the third man, Katz, was not armed. Terry and Chilton were arrested and charged with carrying concealed weapons.