What federal case is known for establishing rules regarding stop and frisk procedures?

The case that established rules regarding stop and frisk procedures is Terry vs. Ohio. In this landmark decision, the Supreme Court ruled that law enforcement officers are permitted to stop an individual on the street and perform a limited pat-down of the person's outer clothing if they have a reasonable suspicion that the person may be armed and involved in criminal activity.

This ruling is significant because it balances the need for effective law enforcement with the protection of individual rights under the Fourth Amendment, which guards against unreasonable searches and seizures. The court found that the need for police officers to act quickly in potentially dangerous situations justified the limited intrusion of a stop and frisk.

The decision outlines the standard of "reasonable suspicion," which is a lower threshold than "probable cause," that officers must meet to conduct a stop. This has shaped the way police conduct stops and has been foundational in training law enforcement officers on the proper procedures for interacting with suspects.