Anonymous Tips and Legality of Traffic Stops
In the case of Navarette v. California, 572 U.S. (2014), the Supreme Court decided on April 22, 2014 that a traffic stop based on an anonymous 911 call was constitutional. In the case, a 911 caller reported that a vehicle had run her off the road. A police officer located the vehicle she identified during the call and executed a traffic stop. The court decided that the totality of the circumstances gave the officer reasonable suspicion that the driver was intoxicated.
In previous court decisions, the "reasonable suspicion" necessary to justify a stop is based on the content of the information possessed by police and its degree of reliability. Alabama v. White, 496 U.S. 325, 330 (1990). The standard takes into account "the totality of the circumstances-the whole picture". In Navarette, the court decided that these principles apply with full force to investigative stops based on information from an anonymous tip. The court decided that, under appropriate circumstances, an anonymous tip can demonstrate "sufficient indicia of reliability to provide reasonable suspicion to make an investigatory stop".
In coming to the conclusion, the court took into account that the caller identified a specific vehicle and reported the license plate and that the caller called 911 within a short time after the incident complained of. The court also determined that the driving complained of by the caller was sufficient for the officer to have a reasonable suspicion of criminal activity. The court stated that a person running another vehicle of the road constituted reasonable suspicion of drunken driving.