Can a police officer have reasonable suspicion for an investigatory stop?

The existence of reasonable suspicion for an investigatory stop is a mixed question of law and fact subject to de novo review. United States v. Rodriguez, 976 F.2d 592, 594 (9th Cir. 1992). The court must look at the "totality of the circumstances" in making its determination. United States v. Sokolow, 490 U.S. 1, 8 (1989).

Police officers may effect a brief, temporary detention without a warrant and without probable cause while attempting to obtain additional information if the officer has a "reasonable suspicion" that a crime is about to be committed, or has taken place. Terry v. Ohio, 392 U.S. 1, 31 (1968).