Florida v. J. L.

An officer, for the protection of himself and others, may conduct a frisk for weapons of persons engaged in unusual conduct where the officer reasonably suspects the person is armed and presently dangerous. Here, the officer’s suspicion that the defendant was carrying a weapon did not develop from his own observations but solely from a call made from an unknown location by an unknown caller. The Court held that this tip lacked sufficient indicia of reliability to provide reasonable suspicion to conduct a frisk. The tip did not provide predictive information that left the government without means to test the informant’s knowledge or credibility. Reasonable suspicion to conduct stops and frisks requires that a tip be reliable in its assertion of illegality, not just in its tendency to identify a person.