CHIEF JUSTICE REHNQUIST delivered the opinion of the Court.

Respondent Wardlow fled upon seeing police officers patrolling an area known for heavy narcotics trafficking. Two of the officers caught up with him, stopped him and conducted a protective pat-down search for weapons. Discovering a .38-caliber handgun, the officers arrested Wardlow. We hold that the officers' stop did not violate the Fourth Amendment to the United States Constitution.

On September 9, 1995, Officers Nolan and Harvey were working as uniformed officers in the special operations section of the Chicago Police Department. The officers were driving the last car of a four car caravan converging on an area known for heavy narcotics trafficking in order to investigate drug transactions. The officers were traveling together because they expected to find a crowd of people in the area, including lookouts and customers.

As the caravan passed 4035 West Van Buren, Officer Nolan observed respondent Wardlow standing next to the building holding an opaque bag. Respondent looked in the direction of the officers and fled. Nolan and Harvey turned their car southbound, watched him as he ran through the gangway and an alley, and eventually cornered him on the street. Nolan then exited his car and stopped respondent. He immediately conducted a protective pat-down search for weapons because in his experience it was common for there to be weapons in the near vicinity of narcotics transactions. During the frisk, Officer Nolan squeezed the bag respondent was carrying and felt a heavy, hard object similar to the shape of a gun. The officer then opened the bag and discovered a .38- caliber handgun with five live rounds of ammunition. The officers arrested Wardlow.

The Illinois trial court denied respondent's motion to suppress, finding the gun was recovered during a lawful stop and frisk Following a stipulated bench trial, Wardlow was convicted of unlawful use of a weapon by a felon. The Illinois Appellate Court reversed Wardlow's conviction, concluding that the gun should have been suppressed because Officer Nolan did not have reasonable suspicion sufficient to justify an investigative stop pursuant to Terry.

The Illinois Supreme Court agreed. While rejecting the Appellate Court's conclusion that Wardlow was not in a high crime area, the Illinois Supreme Court determined that sudden flight in such an area does not create a reasonable suspicion justifying a Terry stop. Relying on Royer, the court explained that although police have the right to approach individuals and ask questions, the individual has no obligation to respond. The person may decline to answer and simply go on his or her way, and the refusal to respond, alone, does not provide a legitimate basis for an investigative stop. The court then determined that flight may simply be an exercise of this right to "go on one's way," and, thus, could not constitute reasonable suspicion justifying a Terry stop.

The Illinois Supreme Court also rejected the argument that flight combined with the fact that it occurred in a high crime area supported a finding of reasonable suspicion because the "high crime area" factor was not sufficient standing alone to justify a Terry stop. Finding no independently suspicious circumstances to support an investigatory detention, the court held that the stop and subsequent arrest violated the Fourth Amendment. We granted certiorari and now reverse.

This case, involving a brief encounter between a citizen and a police officer on a public street, is governed by the analysis we first applied in Terry. . . .

Nolan and Harvey were among eight officers in a four car caravan that was converging on an area known for heavy narcotics trafficking, and the officers anticipated encountering a large number of people in the area, including drug customers and individuals serving as lookouts. It was in this context that Officer Nolan decided to investigate Wardlow after observing him flee. An individual's presence in an area of expected criminal activity, standing alone, is not enough to support a reasonable, particularized suspicion that the person is committing a crime. But officers are not required to ignore the relevant characteristics of a location in determining whether the circumstances are sufficiently suspicious to warrant further investigation. Accordingly, we have previously noted the fact that the stop occurred in a "high crime area" among the relevant contextual considerations in a Terry analysis.

In this case, moreover, it was not merely respondent's presence in an area of heavy narcotics trafficking that aroused the officers' suspicion but his unprovoked flight upon noticing the police. Our cases have also recognized that nervous, evasive behavior is a pertinent factor in determining reasonable suspicion. Headlong flight--wherever it occurs-- is the consummate act of evasion: it is not necessarily indicative of wrongdoing, but it is certainly suggestive of such. In reviewing the propriety of an officer's conduct, courts do not have available empirical studies dealing with inferences drawn from suspicious behavior, and we cannot reasonably demand scientific certainty from judges or law enforcement officers where none exists. Thus, the determination of reasonable suspicion must be based on commonsense judgments and inferences about human behavior. We conclude Officer Nolan was justified in suspecting that Wardlow was involved in criminal activity, and, therefore, in investigating further.

Such a holding is entirely consistent with our decision in Royer, where we held that when an officer, without reasonable suspicion or probable cause, approaches an individual, the individual has a right to ignore the police and go about his business. And any "refusal to cooperate, without more, does not furnish the minimal level of objective justification needed for a detention or seizure." Bostick. But unprovoked flight is simply not a mere refusal to cooperate. Flight, by its very nature, is not "going about one's business"; in fact, it is just the opposite. Allowing officers confronted with such flight to stop the fugitive and investigate further is quite consistent with the individual's right to go about his business or to stay put and remain silent in the face of police questioning.

Respondent and amici also argue that there are innocent reasons for flight from police and that, therefore, flight is not necessarily indicative of ongoing criminal activity. This fact is undoubtedly true, but does not establish a violation of the Fourth Amendment. Even in Terry, the conduct justifying the stop was ambiguous and susceptible of an innocent explanation. . . .

In allowing such detentions, Terry accepts the risk that officers may stop innocent people. Indeed, the Fourth Amendment accepts that risk in connection with more drastic police action; persons arrested and detained on probable cause to believe they have committed a crime may turn out to be innocent. The Terry stop is a far more minimal intrusion, simply allowing the officer to briefly investigate further. If the officer does not learn facts rising to the level of probable cause, the individual must be allowed to go on his way. But in this case the officers found respondent in possession of a handgun, and arrested him for violation of an Illinois firearms statute. No question of the propriety of the arrest itself is before us.

The judgment of the Supreme Court of Illinois is reversed. . . .

Justice Stevens, with whom Justice Souter, Justice Ginsburg, and Justice Breyer join, concurring in part and dissenting in part.

The State of Illinois asks this Court to announce a "bright-line rule" authorizing the temporary detention of anyone who flees at the mere sight of a police officer. Respondent counters by asking us to adopt the opposite per se rule--that the fact that a person flees upon seeing the police can never, by itself, be sufficient to justify a temporary investigative stop of the kind authorized by Terry.

The Court today wisely endorses neither per se rule. Instead, it rejects the proposition that "flight is ... necessarily indicative of ongoing criminal activity," adhering to the view that "[t]he concept of reasonable suspicion . . . is not readily, or even usefully, reduced to a neat set of legal rules," but must be determined by looking to "the totality of the circumstances--the whole picture." Abiding by this framework, the Court concludes that "Officer Nolan was justified in suspecting that Wardlow was involved in criminal activity."

Although I agree with the Court's rejection of the per se rules proffered by the parties, unlike the Court, I am persuaded that in this case the brief testimony of the officer who seized respondent does not justify the conclusion that he had reasonable suspicion to make the stop. Before discussing the specific facts of this case, I shall comment on the parties' requests for a per se rule.

I

. . . The question in this case concerns "the degree of suspicion that attaches to" a person's flight--or, more precisely, what "commonsense conclusions" can be drawn respecting the motives behind that flight. A pedestrian may break into a run for a variety of reasons--to catch up with a friend a block or two away, to seek shelter from an impending storm, to arrive at a bus stop before the bus leaves, to get home in time for dinner, to resume jogging after a pause for rest, to avoid contact with a bore or a bully, or simply to answer the call of nature--any of which might coincide with the arrival of an officer in the vicinity. A pedestrian might also run because he or she has just sighted one or more police officers. In the latter instance, the State properly points out "that the fleeing person may be, inter alia, (1) an escapee from jail; (2) wanted on a warrant, (3) in possession of contraband, (i.e. drugs, weapons, stolen goods, etc.); or (4) someone who has just committed another type of crime." In short, there are unquestionably circumstances in which a person's flight is suspicious, and undeniably instances in which a person runs for entirely innocent reasons.

Given the diversity and frequency of possible motivations for flight, it would be profoundly unwise to endorse either per se rule. The inference we can reasonably draw about the motivation for a person's flight, rather, will depend on a number of different circumstances. Factors such as the time of day, the number of people in the area, the character of the neighborhood, whether the officer was in uniform, the way the runner was dressed, the direction and speed of the flight, and whether the person's behavior was otherwise unusual might be relevant in specific cases. This number of variables is surely sufficient to preclude either a bright-line rule that always justifies, or that never justifies, an investigative stop based on the sole fact that flight began after a police officer appeared nearby. true, however, that the innocent explanations make the single act of flight sufficiently ambiguous to preclude the adoption of a per se rule.

Still, Illinois presses for a per se rule regarding "unprovoked flight upon seeing a clearly identifiable police officer." The phrase "upon seeing," as used by Illinois, apparently assumes that the flight is motivated by the presence of the police officer. Illinois contends that unprovoked flight is "an extreme reaction," because innocent people simply do not "flee at the mere sight of the police." To be sure, Illinois concedes, an innocent person--even one distrustful of the police--might "avoid eye contact or even sneer at the sight of an officer," and that would not justify a Terry stop or any sort of per se inference. But, Illinois insists, unprovoked flight is altogether different. Such behavior is so "aberrant" and "abnormal" that a per se inference is justified.

Even assuming we know that a person runs because he sees the police, the inference to be drawn may still vary from case to case. Flight to escape police detection, we have said, may have an entirely innocent motivation . . . .

In addition . . . a reasonable person may conclude that an officer's sudden appearance indicates nearby criminal activity. And where there is criminal activity there is also a substantial element of danger-- either from the criminal or from a confrontation between the criminal and the police. These considerations can lead to an innocent and understandable desire to quit the vicinity with all speed.,

Among some citizens, particularly minorities and those residing in high crime areas, there is also the possibility that the fleeing person is entirely innocent, but, with or without justification, believes that contact with the police can itself be dangerous, apart from any criminal activity associated with the officer's sudden presence. For such a person, unprovoked flight is neither "aberrant" nor "abnormal." Moreover, these concerns and fears are known to the police officers themselves, and are validated by law enforcement investigations into their own practices. Accordingly, the evidence supporting the reasonableness of these beliefs is too pervasive to be dismissed as random or rare, and too persuasive to be disparaged as inconclusive or insufficient. In any event, just as we do not require "scientific certainty" for our commonsense conclusion that unprovoked flight can sometimes indicate suspicious motives, neither do we require scientific certainty to conclude that unprovoked flight can occur for other, innocent reasons.

The probative force of the inferences to be drawn from flight is a function of the varied circumstances in which it occurs. Sometimes those inferences are entirely consistent with the presumption of innocence, sometimes they justify further investigation, and sometimes they justify an immediate stop and search for weapons. . . .

"Unprovoked flight," in short, describes a category of activity too broad and varied to permit a per se reasonable inference regarding the motivation for the activity. While the innocent explanations surely do not establish that the Fourth Amendment is always violated whenever someone is stopped solely on the basis of an unprovoked flight, neither do the suspicious motivations establish that the Fourth Amendment is never violated when a Terry stop is predicated on that fact alone. For these reasons, the Court is surely correct in refusing to embrace either per se rule advocated by the parties. The totality of the circumstances, as always, must dictate the result.

II

Guided by that totality-of-the-circumstances test, the Court concludes that Officer Nolan had reasonable suspicion to stop respondent. In this respect, my view differs from the Court's. The entire justification for the stop is articulated in the brief testimony of Officer Nolan. Some facts are perfectly clear; others are not. This factual insufficiency leads me to conclude that the Court's judgment is mistaken.

Officer Nolan and his partner were in the last of the four patrol cars that "were all caravaning eastbound down Van Buren." Nolan first observed respondent "in front of 4035 West Van Buren." Wardlow "looked in our direction and began fleeing." Nolan then "began driving southbound down the street observing [respondent] running through the gangway and the alley southbound," and observed that Wardlow was carrying a white, opaque bag under his arm. After the car turned south and intercepted respondent as he "ran right towards us," Officer Nolan stopped him and conducted a "protective search," which revealed that the bag under respondent's arm contained a loaded handgun.

This terse testimony is most noticeable for what it fails to reveal. Though asked whether he was in a marked or unmarked car, Officer Nolan could not recall the answer. He was not asked whether any of the other three cars in the caravan were marked, or whether any of the other seven officers were in uniform. Though he explained that the size of the caravan was because "[n]ormally in these different areas there's an enormous amount of people, sometimes lookouts, customers," Officer Nolan did not testify as to whether anyone besides Wardlow was nearby 4035 West Van Buren. Nor is it clear that that address was the intended destination of the caravan. As the Appellate Court of Illinois interpreted the record, "it appears that the officers were simply driving by, on their way to some unidentified location, when they noticed defendant standing at 4035 West Van Buren." Officer Nolan's testimony also does not reveal how fast the officers were driving. It does not indicate whether he saw respondent notice the other patrol cars. And it does not say whether the caravan, or any part of it, had already passed Wardlow by before he began to run.

Indeed, the Appellate Court thought the record was even "too vague to support the inference that . . . defendant's flight was related to his expectation of police focus on him." Presumably, respondent did not react to the first three cars, and we cannot even be sure that he recognized the occupants of the fourth as police officers. The adverse inference is based entirely on the officer's statement: "He looked in our direction and began fleeing."

No other factors sufficiently support a finding of reasonable suspicion. Though respondent was carrying a white, opaque bag under his arm, there is nothing at all suspicious about that. Certainly the time of day--shortly after noon--does not support Illinois' argument. Nor were the officers "responding to any call or report of suspicious activity in the area." Officer Nolan did testify that he expected to find "an enormous amount of people," including drug customers or lookouts, and the Court points out that "[i]t was in this context that Officer Nolan decided to investigate Wardlow after observing him flee." This observation, in my view, lends insufficient weight to the reasonable suspicion analysis; indeed, in light of the absence of testimony that anyone else was nearby when respondent began to run, this observation points in the opposite direction.

The State, along with the majority of the Court, relies as well on the assumption that this flight occurred in a high crime area. Even if that assumption is accurate, it is insufficient because even in a high crime neighborhood unprovoked flight does not invariably lead to reasonable suspicion. On the contrary, because many factors providing innocent motivations for unprovoked flight are concentrated in high crime areas, the character of the neighborhood arguably makes an inference of guilt less appropriate, rather than more so. Like unprovoked flight itself, presence in a high crime neighborhood is a fact too generic and susceptible to innocent explanation to satisfy the reasonable suspicion inquiry.

It is the State's burden to articulate facts sufficient to support reasonable suspicion. In my judgment, Illinois has failed to discharge that burden. I am not persuaded that the mere fact that someone standing on a sidewalk looked in the direction of a passing car before starting to run is sufficient to justify a forcible stop and frisk.

I therefore respectfully dissent from the Court's judgment to reverse the court below.