dissenting.
The Court today concludes that agents of the Drug Enforcement Administration (DEA) acted lawfully in stopping a traveler changing planes in an airport terminal and escorting her to a DEA office for a strip-search of her person. This result is particularly curious because a majority of the Members of the Court refuse to reject the conclusion that Ms. Mendenhall was “seized,” while a separate majority decline to hold that there were reasonable grounds to justify a seizure. Mr. Justice Stewart concludes that the DEA agents acted lawfully, regardless of whether there were any reasonable grounds for suspecting Ms. Mendenhall of criminal activity, because he finds that Ms. Mendenhall was not “seized” by the DEA agents, even though throughout the proceedings below the Government never questioned the fact that a seizure had occurred necessitating a showing of antecedent reasonable suspicion. Mr. Justice Powell’s opinion concludes that even though Ms. Mendenhall may have been “seized,” the seizure was lawful because her behavior while changing planes in the airport provided reasonable suspicion that she was engaging in criminal activity. The Court then concludes, based on the absence of evidence that Ms. Menden-hall resisted her detention, that she voluntarily consented to being taken to the DEA office, even though she in fact had no choice in the matter. This conclusion is inconsistent with our recognition that consent cannot be presumed from a *567showing of acquiescence to authority, and it cannot be reconciled with our decision last Term in Dunaway v. New York, 442 U. S. 200 (1979).
I
Beginning with Terry v. Ohio, 392 U. S. 1, 16 (1968), the Court has recognized repeatedly that the Fourth Amendment’s proscription of unreasonable “seizures” protects individuals during encounters with police that do not give rise to an arrest. United States v. Brignoni-Ponce, 422 U. S. 873, 878 (1976); United States v. Martinez-Fuerte, 428 U. S. 543, 556 (1976); Delaware v. Prouse, 440 U. S. 648, 653 (1979). In Terry we “emphatically reject[ed]” the notion that a “stop” “is outside the purview of the Fourth Amendment because ... [it is not a] ‘seizure’ within the meaning of the Constitution.” 392 U. S., at 16. We concluded that “the sounder course is to recognize that the Fourth Amendment governs all intrusions by agents of the public upon personal security, and to make the scope of the particular intrusion, in light of all the exigencies of the case, a central element in the analysis of reasonableness.” Id., at 18, n. 15. Applying this principle,
“[w]e have recognized that in some circumstances an officer may detain a suspect briefly for questioning although he does not have ‘probable cause’ to believe that the suspect is involved in criminal activity, as is required for a traditional arrest. However, we have required the officers to have a reasonable suspicion, based on objective facts, that the individual is involved in criminal activity.” Brown v. Texas, 443 U. S. 47, 51 (1979) (citations omitted).
Throughout the lower court proceedings in this case, the Government never questioned that the initial stop of Ms. Mendenhall was a “seizure” that required reasonable suspicion. Rather, the Government sought to justify the stop by arguing that Ms. Mendenhall’s behavior had given rise to *568reasonable suspicion because it was consistent with portions of the so-called “drug courier profile,” an informal amalgam of characteristics thought to be associated with persons carrying illegal drugs.1 Having failed to convince the Court of Appeals that the DEA agents had reasonable suspicion for the stop, the Government seeks reversal here by arguing for the first time that no “seizure” occurred, an argument that Mr. Justice Stewart now accepts, thereby pretermitting the question whether there was reasonable suspicion to stop Ms. Mendenhall. Mr. Justice Stewart’s opinion not only is *569inconsistent with our usual refusal to reverse judgments on grounds not raised below, but it also addresses a fact-bound question with a totality-of-circumstances assessment that is best left in the first instance to the trial court, particularly since the question was not litigated below and hence we cannot be sure is adequately addressed by the record before us.2
Mr. Justice Stewart believes that a “seizure” within the meaning of the Fourth Amendment occurs when an individual’s freedom of movement is restrained by means of physical force or a show of authority. Although it is undisputed that Ms. Mendenhall was not free to leave after the DEA agents stopped her and inspected her identification, App. 19, Mr. Justice Stewart concludes that she was not “seized” because he finds that, under the totality of the circumstances, *570a reasonable person would have believed that she was free to leave. While basing this finding on an alleged absence from the record of objective evidence indicating that Ms. Menden-hall was not free to ignore the officer’s inquiries and continue on her way, Mr. Justice Stewart’s opinion brushes off the fact that this asserted evidentiary deficiency may be largely attributable to the fact that the “seizure” question was never raised below. In assessing what the record does reveal, the opinion discounts certain objective factors that would tend to support a “seizure” finding,3 while relying on contrary factors inconclusive even under its own illustrations of how a “seizure” may be established.4 Moreover, although Mr. Justice Stewart’s opinion purports to make its “seizure” finding turn on objective factors known to the person accosted, in distinguishing prior decisions holding that investigatory stops constitute “seizures,” it does not rely on differences in the extent to which persons accosted could reasonably believe that they were free to leave.5 Even if one *571believes the Government should be permitted to raise the “seizure” question in this Court, the proper course would be to direct a remand to the District Court for an evidentiary-hearing on the question, rather than to decide it in the first instance in this Court.6
II
Assuming, as we should, that Ms. Mendenhall was “seized” within the meaning of the Fourth Amendment when she was stopped by the DEA agents, the legality of that stop turns on whether there were reasonable grounds for suspecting her of criminal activity at the time of the stop. Brown v. Texas, 443 U. S., at 51. To establish that there was reasonable suspicion for the stop, it was necessary for the police at least to “be able to point to specific and articulable facts which, taken together with rational inferences from those facts, reasonably warrant that intrusion.” Terry v. Ohio, 392 U. S., at 21.
At the time they stopped Ms. Mendenhall, the DEA agents’ suspicion that she was engaged in criminal activity was based solely on their brief observations of her conduct at the airport.7 The officers had no advance information that Ms. Men-*572denhall, or anyone on her flight, would be carrying drugs. What the agents observed Ms. Mendenhall do in the airport was not “unusual conduct” which would lead an experienced officer reasonably to conclude that criminal activity was afoot, id., at 30, but rather the kind of behavior that could reasonably be expected of anyone changing planes in an airport terminal.
None of the aspects of Ms. Mendenhall’s conduct, either alone or in combination, were sufficient to provide reasonable suspicion that she was engaged in criminal activity. The fact that Ms. Mendenhall was the last person to alight from a flight originating in Los Angeles was plainly insufficient to provide a basis for stopping her. Nor was the fact that her flight originated from a “major source city,” for the mere proximity of a person to areas with a high incidence of drug activity or to persons known to be drug addicts, does not provide the necessary reasonable suspicion for an investigatory stop. Ybarra v. Illinois, 444 U. S. 85 (1979); Brown v. Texas, supra; Sibron v. New York, 392 U. S. 40, 62 (1968).8 *573Under the circumstances of this case, the DEA agents’ observations that Ms. Mendenhall claimed no luggage and changed airlines were also insufficient to provide reasonable suspicion. Unlike the situation in Terry v. Ohio, 392 U. S., at 28, where “nothing in [the suspects’] conduct from the time [the officer] first noticed them until the time he confronted them and identified himself as a police officer gave him sufficient reason to negate [his] hypothesis” of criminal behavior, Ms. Mendenhall’s subsequent conduct negated any reasonable inference that she was traveling a long distance without luggage or changing her ticket to a different airline to avoid detection. Agent Anderson testified that he heard the ticket agent tell Ms. Mendenhall that her ticket to Pittsburgh already was in order and that all she needed was a boarding pass for the flight.9 Thus it should have been plain to an experienced observer that Ms. Mendenhall’s failure to claim luggage was attributable to the fact that she was already ticketed through to Pittsburgh on a different airline.10 Because Agent Anderson’s suspicion that Ms. Mendenhall was transporting narcotics could be based only on “his inchoate and unparticularized suspicion or hunch,’ ” rather than “specific reasonable inferences which he is entitled to draw from the facts in light of his experience,” id., at 27, he was not justified in “seizing” Ms. Mendenhall.11
*574Ill
Whatever doubt there may be concerning whether Ms. Men-denhall’s Fourth Amendment interests were implicated during the initial stages of her confrontation with the DEA agents, she undoubtedly was “seized” within the meaning of the Fourth Amendment when the agents escorted her from the public area of the terminal to the DEA office for questioning and a strip-search of her person. In Dunaway v. New York, 442 U. S. 200 (1979), we held that a person who accompanied police officers to a police station for purposes of interrogation undoubtedly “was 'seized’ in the Fourth Amendment sense,” even though “he was not told he was under arrest.” Id., at 207, 203. We found it significant that the suspect was taken to a police station, “was never informed that he was 'free to go,’ ” and “would have been physically restrained if he had refused to accompany the officers or had-tried to escape their custody.” Id., at 212. Like the “seizure” in Dunaway, the nature of the intrusion to which Ms.. Mendenhall was subjected when she was escorted by DEA agents to their office and detained there for questioning and a strip-search was so great that it “was in important respects indistinguishable from a traditional arrest.” Ibid. Although Ms. Mendenhall was not told that she was under arrest, she in fact was not free to refuse to go to the DEA office *575and was not told that she was.12 Furthermore, once inside the office, Ms. Mendenhall would not have been permitted to leave without submitting to a strip-search.13 Thus, as in Dunaway,
“[t]he mere facts that [the suspect] was not told he was under arrest, was not ‘booked,’ and would not have had an arrest record if the interrogation had proved fruitless, while not insignificant for all purposes, obviously do not make [the suspect’s] seizure even roughly analogous to the narrowly defined intrusions involved in Terry and its progeny.” Id., at 212-213 (citation omitted).
Because the intrusion to which Ms. Mendenhall was subjected when she was escorted to the DEA office is of the same character as that involved in Dunaway, probable cause, which con-cededly was absent, was required to support the intrusion.
The Court’s suggestion that no Fourth Amendment interest possessed by Ms. Mendenhall was implicated because she consented to go to the DEA office is inconsistent with Dun-*576away and unsupported in the record. There was no evidence in the record to support the District Court’s speculation, made before Dunaway was decided, that Ms. Mendenhall accompanied “Agent Anderson to the airport DEA Office Voluntarily in a spirit of apparent cooperation with the [agent’s] investigation,’ Sibron v. New York, 392 U. S. 40, 63 (1968).” App. to Pet. for Cert. 16a. Ms. Mendenhall did not testify at the suppression hearing and the officers presented no testimony concerning what she said, if anything, when informed that the officers wanted her to come with them to the DEA office. Indeed, the only testimony concerning what occurred between Agent Anderson’s “request” and Ms. Mendenhall’s arrival at the DEA office is the agent’s testimony that if Ms. Mendenhall had wanted to leave at that point she would have been forcibly restrained. The evidence of consent here is even flimsier than that we rejected in Dunaway where it was claimed that the suspect made an affirmative response when asked if he would accompany the officers to the police station. Dunaway v. New York, supra, at 223 (Rehnquist, J., dissenting). Also in Sibron v. New York, from which the District Court culled its description of Ms. Mendenhall’s “consent,” we described a record in a similar state as “totally barren of any indication whether Sibron accompanied Patrolman Martin outside in submission to a show of force or authority which left him no choice, or whether he went voluntarily in a spirit of apparent cooperation with the officer’s investigation.” 392 U. S., at 63.14
The Court recognizes that the Government has the burden of proving that Ms. Mendenhall consented to accompany the officers, but it nevertheless holds that the “totality of evidence was plainly adequate” to support a finding of consent. *577On the record before us, the Court’s conclusion can only be based on the notion that consent can be assumed from the absence of proof that a suspect resisted police authority. This is a notion that we have squarely rejected. In Bumper v. North Carolina, 391 U. S. 543, 548-549 (1968), the Court held that the prosecution’s “burden of proving that the consent was, in fact, freely and voluntarily given . . . cannot be discharged by showing no more than acquiescence to a claim of lawful authority.” (Footnotes omitted.) Johnson v. United States, 333 U. S. 10 (1948); Amos v. United States, 255 U. S. 313 (1921). While the Government need not prove that Ms. Mendenhall knew that she had a right to refuse to accompany the officers, Schneckloth v. Bustamonte, 412 U. S. 218 (1973), it cannot rely solely on acquiescence to the officers’ wishes to establish the requisite consent. The Court of Appeals properly understood this in rejecting the District Court’s “findings” of consent.
Since the defendant was not present to testify at the suppression hearing, we can only speculate about her state of mind as her encounter with the DEA agents progressed from surveillance, to detention, to questioning, to seclusion in a private office, to the female officer’s command to remove her clothing. Nevertheless, it is unbelievable15 that this sequence of events involved no invasion of a citizen’s constitutionally protected interest in privacy. The rule of law requires a different conclusion.
Because Ms. Mendenhall was being illegally detained at the time of the search of her person, her suppression motion should have been granted in the absence of evidence to dissipate the taint.
On August 18, 1976, the Government argued in its answer to Ms. Men-denhall’s suppression motion that the “investigatory stop” of Ms. Menden-hall was reasonable in light of the observations made by the DEA agents. At the suppression hearing on October 18, 1976, Agent Anderson’s testimony focused on explanation of the “drug courier profile,” description of Ms. Mendenhall’s behavior prior to the stop, and discussion of why he thought it suspicious. The United States Attorney at the suppression hearing told the court that “it is the Government’s contention here that we have a valid investigatory stop, followed by a consent to search.” App. 28. Noting that “[u]nder Terry v. Ohio, in order for it to be a valid stop,” there must be “a reasonable suspicion that there was a crime afoot,” the Government argued that the observations and experience of the DEA agents warranted a finding that reasonable suspicion existed to justify the stop. Id., at 28-30. The District Court denied the suppression motion, holding that Agent Anderson had reasonable suspicion to justify “a Terry type intrusion in order to determine defendant’s identity and obtain more information. . . .” App. to Pet. for Cert. 15a.
There is no indication that the Government on appeal, before either the original panel of the Court of Appeals or the en banc court, ever questioned the understanding that the stop of Ms. Mendenhall constituted a “seizure” requiring reasonable suspicion. Neither the majority of the en bane court nor the dissenting judge questioned the District Court’s acknowledgment that reasonable suspicion was required to justify the initial stop of 'Ms. Mendenhall. Even in its petition for certiorari, the Government did not ask this Court to review the question whether a “seizure” had occurred. In the course of arguing that the quantum of suspicion necessary to justify the stop was slight, the Government did note that it was “arguable” that Ms. Mendenhall had not been “seized,” but it was content to assume that she had been. Pet. for Cert. 19.
Mr. Justice Stewart’s suggestion that “exceptional circumstances” justify entertaining the Government’s claim that no seizure occurred, even though it was not raised below, ante, at 551, n. 5, is as curious as his notion that the evidentiary record “is adequate to permit consideration of the contention.” Ante, at 552, n. 5. The principal question throughout the controversy over the initial stop was no^ “whether the respondent was at any time detained by the DEA agents,” ibid., but rather whether there was reasonable suspicion to support the stop. See ante, at 547, n. 1. While there was no material factual dispute concerning what the DEA agents observed that allegedly gave rise to reasonable suspicion, once the Government raised the “seizure” question before this Court, there were substantial differences between the parties concerning the nature of the encounter between Ms. Mendenhall and the DEA agents. Thus the District Court’s assumption that Ms. Mendenhall had been “seized” was not based on “a serious misapprehension of federal constitutional law,” ante, at 551, n. 5, for it just as easily could have been based on a different understanding of what the facts would show were the “seizure” question addressed in the District Court, Equally deficient is the suggestion in Mr. Justice Stewart’s opinion that “exceptional circumstances” exist because “determination of the [‘seizure’] question is essential to the correct disposition of the other issues in the case.” Ibid. While the assumption that a “seizure” occurred makes it necessary to reach the question whether there was reasonable suspicion for the stop, it would not affect the way in which that question would be decided when reached.
Not the least of these factors is the fact that the DEA agents for a time took Ms. Mendenhall’s plane ticket and driver’s license from her. It is doubtful that any reasonable person about to board a plane would feel free to leave when law enforcement officers have her plane ticket.
Mr. Justice Stewart notes, for example, that a “seizure” might be established even if the suspect did not attempt to leave, by the nature of the language or tone of voice used by the officers, factors that were never addressed at the suppression hearing, very likely because the “seizure” question was not raised.
In Brown v. Texas, 443 U. S. 47, 51 (1979), and United States v. Brignoni-Ponce, 422 U. S. 873 (1975), the prosecution, as here, did not question whether the suspects who had been stopped had been “seized,” given its concessions that the suspects would not have been permitted to leave without responding to the officers’ requests for identification. In each case the Court recognized that a “seizure” had occurred without inquiring into whether a reasonable person would have believed that he was not free to leave. Mr. Justice Stewart’s present attempt to distinguish the fact that stops of automobiles constitute “seizures,” on the ground that it is more intrusive to visually inspect the passenger compartment of a car, confuses the question of the quantum of reasonable suspicion neces*571sary to justify such “seizures” with the question whether a “seizure” has occurred.
We found that exceptional circumstances warranted consideration of a question not raised below in Youakim v. Miller, 425 U. S. 231, 234-235 (1976), which is cited in Mr. Justice Stewart’s opinion, but there we vacated the judgment and remanded the case, holding that “the claim should be aired first in the District Court.” Id., at 236. Cf. Rios v. United States, 364 U. S. 253 (1960) (remanding to the trial court for determination of when an arrest occurred, after deciding probable-cause question).
Officer Anderson, the DEA agent who testified at the suppression hearing, stated on cross-examination:
“Q. Did you have a tip in this case?
“A. No.
“Q. You were going strictly on what you saw in the airport, is that right?
*572“A. A number of things, what my observations, her response to statements.
“Q. I'm just asking—
“A. (Interposing) All right. Itinerary.
“Q. You’re going on what happened on February 10 without any prior information?
“A. Correct.
“Q. You did not know that Sylvia Mendenhall was traveling to Detroit with narcotics, did you?
“A. No.
“Q. Nor any Negro female traveling from Los Angeles on that date carrying narcotics, did you?
“A. No.” App 18.
If “[t)he inference that persons who talk to narcotics addicts are engaged in the criminal traffic in narcotics is simply not the sort of reasonable inference required to support an intrusion by the police upon an individual’s personal security,” Sibron v. New York, 392 U. S., at 62, then the fact that a person is on a flight that originated from a njajor “source city” certainly is not.
Agent Anderson testified on cross-examination at the suppression hearing that he believed Ms. Mendenhall’s failure to pick up luggage was suspicious only before he learned that she was changing planes. App. 16.
We recognized in Brown v. Texas, 443 U. S., at 52, n. 2, that “a trained, experienced police officer [may be] able to perceive and articulate meaning in given conduct which would be wholly innocent to the untrained observer.” By the same token, Agent Anderson’s experience on airport detail may be considered as negating any reasonable inference that Ms. Mendenhall’s behavior was suspicious once he learned that she only needed a boarding pass for her flight to Pittsburgh.
Mr. Justice Powell’s conclusion that there were reasonable grounds for suspecting Ms. Mendenhall of criminal activity relies heavily on the assertion that the DEA agents “acted pursuant to a well-planned, and *574effective, federal law enforcement program.” Ante, at 565. Yet there is no indication that the asserted successes of the “drug courier program” have been obtained by reliance on the kind of nearly random stop involved in this case. Indeed, the statistics MR. Justice Powell cites on the success of the program at the Detroit Airport, ante, at 562, refer to the results of searches following stops “based upon information acquired from the airline ticket agents, from [the agents’] independent police work,” and occasional tips, as well as observations of behavior at the airport. United States v. Van Lewis, 409 F. Supp. 535, 538 (ED Mich. 1976), aff’d, 556 F. 2d 385 (CA6 1977). Here, however, it is undisputed that the DEA agents’ suspicion that Ms. Mendenhall was engaged in criminal activity was based solely on their observations of her conduct in the airport terminal. Supra, at 571-572, n. 7.
Agent Anderson testified on cross-examination at the suppression hearing:
“Q. All right. Now, when you asked her to accompany you to the DEA office for further questioning, if she had wanted to walk away, would you have stopped her?
“A. Once I asked her to accompany me?
“Q. Yes.
“A. Yes, I would have stopped her.
“Q. She was not free to leave, was she?
“A. Not at that point.” App. 19.
Agent Anderson testified:
“Q. Had she tried to leave that room when she was being accompanied by the female officer, would you have known?
“A. If she had attempted to leave the room ?
“Q. Yes.
“A. Well yes, I could say that I would have known.
“Q. And if she had tried to leave prior to being searched by the female officer, would you have stopped her?
“A. Yes.” Id., at 21.
In Sibron v. New York, 392 U. S., at 45, we noted that the record revealed only that "Sibron sat down and ordered pie and coffee, and, as he was eating, Patrolman Martin approached him and told him to come outside. Once outside, the officer said to Sibron, ‘You know what I am after.’ ”
“wm you walk into my parlour?” said the spider to a fly.
(You may find you have consented, without ever knowing why.)