Is An Anonymous Call and Subsequent Police Corroboration Sufficient to Establish Reasonable Suspicion for Investigatory Stop ?

In Commonwealth v. Jackson, 548 Pa. 484, 698 A.2d 571 (1997), an officer responded to a police radio broadcast that a man of a particular description was carrying a gun. The source of the report was unknown. The Court held that the anonymous call and subsequent police corroboration was insufficient to establish reasonable suspicion to support an investigatory stop. The Court observed that if police "respond to an anonymous call that a particular person at a specified location is engaged in criminal activity, and upon arriving at the location see a person matching the description and nothing more, they have no certain knowledge except that the caller accurately described someone at a particular location." 547 Pa. at 656-657, 692 A.2d at 1070. The same can be said of an anonymous tip that "predicts" an accused's location, physical appearance, and an unsuspicious routine activity.