The Supreme Court of the United States held that a policeman is justified in making a search for weapons in the outer clothing of one who he reasonably suspects is armed and dangerous, even though the policeman has no probable cause to arrest the man he is detaining.
Terry v. State of Ohio, 88 S. Ct. 1868 (1968).
Criminal Law - Searches and Seizures,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol7/iss1/19