529 U.S. 266 (2000)
Florida v. J.L.
Whether an anonymous tip that a person is carrying a gun, without sufficient indicia of reliability about the tipster's knowledge or the alleged criminal activity, provides reasonable suspicion to justify a Terry stop-and-frisk under the Fourth Amendment.
Under Terry v. Ohio, police may conduct a brief investigatory stop and a protective frisk when they have reasonable suspicion, based on specific and articulable facts and rational inferences, that criminal activity is afoot and the person may be armed and dangerous. Anonymous tips can contribute to reasonable suspicion only if they bear sufficient indicia of reliability—typically through predictive information, an explanation of the basis of knowledge, or corroboration that relates to the assertion of illegality, not merely to readily observable, innocent details like identity and location. There is no categorical "firearm exception" that permits a stop-and-frisk based solely on an uncorroborated anonymous allegation of gun possession.
No. An uncorroborated anonymous tip that a person is carrying a gun, which merely describes the person's appearance and location but lacks indicia of reliability regarding illegal conduct, does not establish reasonable suspicion to justify a Terry stop-and-frisk. The search violated the Fourth Amendment, and suppression of the firearm was proper. Affirmed.
Florida v. J.L. is a foundational case on informant reliability and reasonable suspicion. It teaches that: (1) identity/location corroboration is not enough—officers must have reliable information indicative of criminal conduct; (2) there is no categorical exception for guns under Terry; and (3) courts distinguish between anonymous tips (requiring strong corroboration) and tips from known or otherwise reliable sources. For students, the case pairs with Terry v. Ohio, Adams v. Williams (crediting tips from known informants), Alabama v. White (predictive anonymous tip sufficed), and later Navarette v. California (where a 911 caller's traceability and contemporaneity supported reliability). J.L. remains the baseline rule against bare, uncorroborated anonymous allegations to justify frisks.