An anonymous caller reported to the Police that a young black male standing at a particular bus stop and wearing a plaid shirt was carrying a gun. Nothing was known about the informant. Two officers were instructed to respond. They arrived at the bus stop about six minutes later and saw three black males 'just hanging out [there].' One of the three, respondent J. L. (D), was wearing a plaid shirt. Apart from the tip, the officers had no reason to suspect any of the three of illegal conduct. The officers did not see a firearm, and D made no threatening or otherwise unusual movements. One of the officers approached D., told him to put his hands up on the bus stop, frisked him, and seized a gun from D's pocket. The second officer frisked the other two individuals, against whom no allegations had been made, and found nothing. D was charged under state law with carrying a concealed firearm without a license and possessing a firearm while under the age of 18. He moved to suppress the gun as the fruit of an unlawful search, and the trial court granted his motion. The intermediate appellate court reversed, but the Supreme Court of Florida quashed that decision and held the search invalid under the Fourth Amendment. The Supreme granted certiorari.