Which case established the legality of "stop and frisk" procedures?

The case that established the legality of "stop and frisk" procedures is Terry v. Ohio. This landmark decision, issued by the Supreme Court in 1968, involved a police officer who conducted a brief stop and pat-down of individuals based on reasonable suspicion that they were armed and involved in criminal activity. The Court ruled that the officer's actions were constitutional under the Fourth Amendment, which protects against unreasonable searches and seizures. It determined that a police officer may stop a person for questioning and perform a limited search for weapons if they have a reasonable belief that the individual is armed and poses a threat to their safety or the safety of others. This case set a precedent for the application of stop and frisk as a legitimate practice in law enforcement, balancing the need for officer safety with individual rights.