OCTOBER TERM, 2001
UNITED STATES v. ARVIZU
CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE NINTH CIRCUIT
No. 00-1519. Argued November 27, 200l-Decided January 15,2002
Respondent was stopped by Border Patrol Agent Stoddard while driving on an unpaved road in a remote area of southeastern Arizona. A search of his vehicle revealed more than 100 pounds of marijuana, and he was charged with possession with intent to distribute. The Federal District Court denied respondent's motion to suppress, citing a number of facts that gave Stoddard reasonable suspicion to stop the vehicle. The Ninth Circuit reversed. In its view, fact-specific weighing of circumstances or other multifactor tests introduced uncertainty and unpredictability into the Fourth Amendment analysis, making it necessary to clearly delimit the factors that an officer may consider in making stops such as this one. It then held that several factors relied upon by the District Court carried little or no weight in the reasonable-suspicion calculus and that the remaining factors were not enough to render the stop permissible.
Held: Considering the totality of the circumstances and giving due weight to the factual inferences drawn by Stoddard and the District Court Judge, Stoddard had reasonable suspicion to believe that respondent was engaged in illegal activity. Because the "balance between the public interest and the individual's right to personal security," United States v. Brignoni-Ponce, 422 U. S. 873, 878, tilts in favor of a standard less than probable cause in brief investigatory stops of persons or vehicles, the Fourth Amendment is satisfied if the officer's action is supported by reasonable suspicion to believe that criminal activity "may be afoot," United States v. Sokolow, 490 U. S. 1, 7. In making reasonablesuspicion determinations, reviewing courts must look at the "totality of the circumstances" of each case to see whether the detaining officer has a "particularized and objective basis" for suspecting legal wrongdoing. See, e. g., United States v. Cortez, 449 U. S. 411, 417-418. This process allows officers to draw on their own experiences and specialized training to make inferences from and deductions about the cumulative information available. Id., at 418. The Ninth Circuit's methodology departs sharply from these teachings, and it reached the wrong result in this case. Its evaluation and rejection of certain factors in isolation from each other does not take into account the "totality of the circum-
stances," as this Court's cases have understood that phrase. The court appeared to believe that each of Stoddard's observations that was by itself susceptible to an innocent explanation was entitled to no weight. Terry v. Ohio, 392 U. S. 1, however, precludes this sort of divide-andconquer analysis. And the court's view that it was necessary to clearly delimit an officer's consideration of certain factors to reduce troubling uncertainty also runs counter to this Court's cases and underestimates the reasonable-suspicion standard's usefulness in guiding officers in the field. The de novo standard for appellate review of reasonablesuspicion determinations has, inter alia, a tendency to unify precedent and a capacity to provide law enforcement officers the tools to reach the correct decision beforehand. Ornelas v. United States, 517 U. S. 690, 691, 697-698. The Ninth Circuit's approach would seriously undermine the "totality of the circumstances" principle governing the existence vel non of "reasonable suspicion." Here, it was reasonable for Stoddard to infer from his observations, his vehicle registration check, and his border patrol experience that respondent had set out on a route used by drug smugglers and that he intended to pass through the area during a border patrol shift change; and Stoddard's assessment of the reactions of respondent and his passengers was entitled to some weight. Although each of the factors alone is susceptible to innocent explanation, and some factors are more probative than others, taken together, they sufficed to form a particularized and objective basis for stopping the vehicle. Pp. 273-278.
232 F.3d 1241, reversed and remanded.
REHNQUIST, C.J., delivered the opinion for a unanimous Court.
SCALIA, J., filed a concurring opinion, post, p. 278.
Austin C. Schlick argued the cause for the United States.
With him on the briefs were Solicitor General Olson, Assistant Attorney General Chertoff, Deputy Solicitor General Dreeben, and Deborah Watson.
Victoria A. Brambl argued the cause for respondent.
With her on the brief was Fredric F. Kay. *
*Briefs of amici curiae urging affirmance were filed for the DKT Liberty Project by Julia M. Carpenter; and for the National Association of Criminal Defense Lawyers et al. by Lawrence S. Lustberg and Risa E. Kaufman.