MR. JUSTICE POWELL delivered the opinion of the Court.
This case raises questions as to the United States Border Patrol's authority to stop automobiles in areas near the Mexican border. It differs from our decision in Almeida-Sanchez v. United States, 413 U.S. 266 (1973), in that the Border Patrol does not claim authority to search cars, but only to question the occupants about their citizenship and immigration status.
As part of its regular traffic-checking operations in southern California, the Border Patrol operates a fixed checkpoint on Interstate Highway 5 south of San Clemente. On the evening of March 11, 1973, the checkpoint was closed because of inclement weather, but two officers were observing northbound traffic from a patrol
Respondent's appeal was pending in the Court of Appeals for the Ninth Circuit when we announced our decision in Almeida-Sanchez v. United States, supra, holding that the Fourth Amendment prohibits the use of roving patrols to search vehicles, without a warrant or probable cause, at points removed from the border and its functional equivalents. The Court of Appeals, sitting en banc, held that the stop in this case more closely resembled a roving-patrol stop than a stop at a traffic checkpoint, and applied the principles of Almeida-Sanchez.
The Government does not challenge the Court of Appeals' factual conclusion that the stop of respondent's car was a roving-patrol stop rather than a checkpoint stop. Brief for United States 8. Nor does it challenge the retroactive application of Almeida-Sanchez, supra, Brief for United States 9, or contend that the San Clemente checkpoint is the functional equivalent of the border. The only issue presented for decision is whether a roving patrol may stop a vehicle in an area near the border and question its occupants when the only ground for suspicion is that the occupants appear to be of Mexican ancestry. For the reasons that follow, we affirm the decision of the Court of Appeals.
The Government claims two sources of statutory authority
Under current regulations, this authority may be exercised anywhere within 100 miles of the border. 8 CFR § 287.1 (a) (1975). The Border Patrol interprets the statute as granting authority to stop moving vehicles and question the occupants about their citizenship, even when its officers have no reason to believe that the occupants are aliens or that other aliens may be concealed in the vehicle.
The Fourth Amendment applies to all seizures of the person, including seizures that involve only a brief detention short of traditional arrest. Davis v. Mississippi, 394 U.S. 721 (1969); Terry v. Ohio, 392 U.S. 1, 16-19 (1968). "[W]henever a police officer accosts an individual and restrains his freedom to walk away, he has `seized' that person," id., at 16, and the Fourth Amendment requires that the seizure be "reasonable." As with other categories of police action subject to Fourth Amendment constraints, the reasonableness of such seizures depends on a balance between the public interest and the individual's right to personal security free from arbitrary interference by law officers. Id., at 20-21; Camara v. Municipal Court, 387 U.S. 523, 536-537 (1967).
The Government makes a convincing demonstration that the public interest demands effective measures to prevent the illegal entry of aliens at the Mexican border. Estimates of the number of illegal immigrants in the United States vary widely. A conservative estimate in 1972 produced a figure of about one million, but the INS now suggests there may be as many as 10 or 12 million aliens illegally in the country.
The Government has estimated that 85% of the aliens illegally in the country are from Mexico. United States v. Baca, 368 F.Supp. 398, 402 (SD Cal. 1973).
Against this valid public interest we must weigh the interference with individual liberty that results when an officer stops an automobile and questions its occupants.
Because of the limited nature of the intrusion, stops of this sort may be justified on facts that do not amount to the probable cause required for an arrest. In Terry v. Ohio, supra, the Court declined expressly to decide whether facts not amounting to probable cause could justify an "investigative `seizure' " short of an arrest, 392 U. S., at 19 n. 16, but it approved a limited search—a pat-down for weapons—for the protection of an officer investigating suspicious behavior of persons he reasonably believed to be armed and dangerous. The Court approved such a search on facts that did not constitute probable cause to believe the suspects guilty of a crime, requiring only that "the police officer . . . be able to point to specific and articulable facts which, taken together with rational inferences from those facts, reasonably warrant" a belief that his safety or that of others is in danger. Id., at 21; see id., at 27.
We elaborated on Terry in Adams v. Williams, 407 U.S. 143 (1972), holding that a policeman was justified
These cases together establish that in appropriate circumstances the Fourth Amendment allows a properly limited "search" or "seizure" on facts that do not constitute probable cause to arrest or to search for contraband or evidence of crime. In both Terry and Adams v. Williams the investigating officers had reasonable grounds to believe that the suspects were armed and that they might be dangerous. The limited searches and seizures in those cases were a valid method of protecting the public and preventing crime. In this case as well, because of the importance of the governmental interest at stake, the minimal intrusion of a brief stop, and the absence of practical alternatives for policing the border, we hold that when an officer's observations lead him reasonably to suspect that a particular vehicle may contain aliens who are illegally in the country, he may stop the car briefly and investigate the circumstances that provoke suspicion. As in Terry, the stop and inquiry must be "reasonably related in scope to the justification for their initiation." 392 U. S., at 29. The officer may question the driver and passengers about their citizenship and
We are unwilling to let the Border Patrol dispense entirely with the requirement that officers must have a reasonable suspicion to justify roving-patrol stops.
We are not convinced that the legitimate needs of law enforcement require this degree of interference with lawful traffic. As we discuss in Part IV, infra, the nature of illegal alien traffic and the characteristics of smuggling operations tend to generate articulable grounds for identifying violators. Consequently, a requirement of reasonable suspicion for stops allows the Government adequate means of guarding the public interest and also protects residents of the border areas from indiscriminate official interference. Under the circumstances, and even though the intrusion incident to a stop is modest, we conclude that it is not "reasonable" under the Fourth Amendment to make such stops on a random basis.
The Government also contends that the public interest in enforcing conditions on legal alien entry justifies stopping persons who may be aliens for questioning about their citizenship and immigration status. Although we
The effect of our decision is to limit exercise of the authority granted by both § 287 (a) (1) and § 287 (a) (3). Except at the border and its functional equivalents, officers on roving patrol may stop vehicles only if they are aware of specific articulable facts, together with rational inferences from those facts, that reasonably warrant suspicion that the vehicles contain aliens who may be illegally in the country.
Any number of factors may be taken into account in deciding whether there is reasonable suspicion to stop a car in the border area. Officers may consider the characteristics of the area in which they encounter a vehicle. Its proximity to the border, the usual patterns
In this case the officers relied on a single factor to justify stopping respondent's car: the apparent Mexican ancestry
The judgment of the Court of Appeals is
[For opinion of THE CHIEF JUSTICE concurring in the judgment, see post, p. 899.]
[For opinion of MR. JUSTICE WHITE concurring in the judgment, see post, p. 914.]
MR. JUSTICE REHNQUIST, concurring.
I join in the opinion of the Court. I think it quite important to point out, however, that that opinion, which is joined by a somewhat different majority than that which comprised the Almeida-Sanchez Court, is both by its terms and by its reasoning concerned only with the type of stop involved in this case. I think that just as travelers entering the country may be stopped and searched without probable cause and without founded suspicion, because of "national self protection reasonably requiring one entering the country to identify himself as entitled to come in, and his belongings as effects which may be lawfully brought in," Carroll v. United States, 267 U.S. 132, 154 (1925), a strong case may be made for those charged with the enforcement of laws conditioning the right of vehicular use of a highway to likewise stop motorists using highways in order to determine whether they have met the qualifications prescribed by applicable law for such use. See Cady v. Dombrowski, 413 U.S. 433, 440-441 (1973); United States v. Biswell, 406 U.S. 311 (1972). I regard these and similar situations, such
MR. JUSTICE DOUGLAS, concurring in the judgment.
I join in the affirmance of the judgment. The stopping of respondent's automobile solely because its occupants appeared to be of Mexican ancestry was a patent violation of the Fourth Amendment. I cannot agree, however, with the standard the Court adopts to measure the lawfulness of the officers' action. The Court extends the "suspicion" test of Terry v. Ohio, 392 U.S. 1 (1968), to the stop of a moving automobile. I dissented from the adoption of the suspicion test in Terry, believing it an unjustified weakening of the Fourth Amendment's protection of citizens from arbitrary interference by the police. I remarked then:
The fears I voiced in Terry about the weakening of the Fourth Amendment have regrettably been borne out by subsequent events. Hopes that the suspicion test might be employed only in the pursuit of violent crime—a limitation endorsed by some of its proponents
The uses to which the suspicion test has been put are illustrated in some of the cases cited in the Court's opinion. In United States v. Wright, 476 F.2d 1027 (CA5 1973), for example, immigration officers stopped a station wagon near the border because there was a spare tire in the back seat. The court held that the officers reasonably suspected that the spare wheel well had been freed in order to facilitate the concealment of aliens. In United States v. Bugarin-Cases, 484 F.2d 853 (CA9 1973), the Border Patrol officers encountered a man driving alone in a station wagon which was "riding low"; stopping the car was held reasonable because the officers suspected that aliens might have been hidden beneath the floorboards. The vacationer whose car is weighted down with luggage will find no comfort in these decisions; nor will the many law-abiding citizens
The Court does, to be sure, disclaim approval of the particular decisions it cites applying the suspicion test. But by specifying factors to be considered without attempting to explain what combination is necessary to satisfy the test, the Court may actually induce the police to push its language beyond intended limits and to advance as a justification any of the enumerated factors even where its probative significance is negligible.
Ultimately the degree to which the suspicion test actually restrains the police will depend more upon what the Court does henceforth than upon what it says today. If my Brethren mean to give the suspicion test a new bite, I applaud the intention. But in view of the developments since the test was launched in Terry, I am not optimistic. This is the first decision to invalidate a stop on the basis of the suspicion standard. In fact, since Terry we have granted review of a case applying the test only once, in Adams v. Williams, 407 U.S. 143 (1972), where the Court found the standard satisfied by the tip from an informant whose credibility was not established and whose information was not shown to be based upon personal knowledge. If in the future the suspicion test is to provide any meaningful restraint of the police, its force must come from vigorous review of its applications, and not alone from the qualifying language of today's opinion. For now, I remain unconvinced that the suspicion test offers significant protection of the "comprehensive right of personal liberty in the face of governmental intrusion," Lopez v. United States, 373 U.S. 427, 455 (1963) (dissenting opinion), that is embodied in the Fourth Amendment.