A dog-sniff at the San Juan international airport alerted authorities to the possible presence of narcotics in four suitcases checked on a domestic flight to New York City. Based on information that indirectly linked defendant Carlos Ruben Acosta-Colon (“Acosta”) to these bags, three law enforcement officials stopped Acosta and two persons traveling with him as they attempted to board the flight. At issue in this appeal is the constitutionality of the ensuing thirty-minute detention that led to Acosta’s formal arrest. Conceding that Acosta was stopped on the basis of suspicion short of probable cause, the government contends that the detention was nevertheless reasonable under the circumstances and fell within the parameters of Terry v. Ohio, 392 U.S. 1, 88 S.Ct. 1868, 20 L.Ed.2d 889 (1968). The district *12court agreed and denied the defendant’s motion to suppress. We now reverse.
I.
The following facts are not materially disputed. At about 11 a.m. on November 3, 1995, a canine narcotics unit working at the Luis Muñoz Marin Airport in Puerto Rico alerted an agent of the United States Customs Department to the odor of drugs in four American Tourister suitcases that had been checked on an American Airlines flight scheduled to depart for New York City at 1 p.m. Two of the four bags had identification tags bearing the name of Miguel Morales; the other two had tags showing the name Jesús Lebrón. Customs officers immediately seized all four pieces of luggage and transported them to what the government describes as the airport’s “customs enclosure area.”
A supervisor in the customs office then requested from American Airlines its computer record of any reservations on the New York City flight in the name of, or connected with, Morales or Lebrón. The airline provided a single computer printout reflecting that Morales and Lebrón both had reserved seats on the flight and had checked two bags each. The printout also showed two other persons — Carlos Acosta and Noel Travieso — as being connected with the Morales/Lebrón reservation, which suggested that all four individuals might be traveling together. The computer record did not indicate that Acosta himself had checked any bags.
At about 12:30 p.m., three customs inspectors dressed in plain clothes were dispatched to the gate from which the New York City flight was to depart. The inspectors stationed themselves in the jetway leading from the gate to the airplane and checked the name on each passenger’s ticket as he or she attempted to board.1 When Acosta, Noel Travieso, and a third suspect unnamed in the record (but evidently known to local authorities) were identified by this method, the inspectors took them boarding passes and instructed them to step to one side of the jetway and wait there until the boarding process was concluded. Acosta complied and was thus detained on the jetway for approximately five minutes. He was not asked any questions during this time.
After all passengers had boarded the plane (neither Morales nor Lebrón having appeared at the gate), the customs inspectors informed Acosta, Travieso, and the third suspect that they were to be taken to a “customs enclosure area” pending investigation of some suspicious baggage. They were not asked to give their consent, and they said nothing in response. Then, without conducting a pat-down or asking any questions, and while they were still on the jetway, the inspectors handcuffed the three suspects to each other, side-by-side, using two sets of restraints. Although the inspectors were armed, they did not display their weapons. The suspects did not resist. The customs inspectors led the three handcuffed suspects, on foot, to the customs enclosure area. The trip, which the government concedes was not voluntary, took approximately six to eight minutes. Acosta and the others missed their flight.
Once the suspects were brought into the customs enclosure area, they were patted down for weapons and, none being found, their handcuffs were removed.2 According to the parties’ stipulation of facts, the three *13suspects were, at this point, “transferred to the custody of the DEA” and were placed in separate rooms that have been variously described in the briefs and at oral argument as “interview,” “interrogation,” or “detention” rooms.3 After Acosta had been left in his interrogation room for approximately 15 minutes — during which time he was never interviewed or questioned — a customs inspector observed him trying to eat two pieces of paper. The inspector entered Acosta’s room and extricated the papers from his mouth. They were baggage claim tickets. The numbers on the tickets matched the tags on the two previously-seized suitcases registered to Jesus Lebrón (which, upon later examination, turned out to contain approximately 15 kilograms of cocaine each). Acosta was advised of his Miranda rights and was formally placed under arrest.4 Waiving his right to remain silent, he made several potentially self-incriminating statements.
Acosta was indicted on one count of possessing cocaine with intent to distribute. Following a plea conference, Acosta filed a motion to suppress, arguing that his airport detention constituted a de facto arrest without probable cause, and that the incriminating baggage claim tickets he had tried to eat and the statements he made to authorities thereafter constituted the fruits of that illegal arrest. After two hearings, and following the parties’ submission of their stipulated statement of facts, the district court denied the defendant’s motion. Acosta subsequently pled guilty pursuant to the terms of a conditional plea agreement, in which he reserved his right to appeal the district court’s ruling on the motion to suppress. The court accepted his plea, and Acosta was accordingly sentenced to 70 months of imprisonment and five years of supervised release.
II.
A.
As a preliminary matter, we think it important to clarify that, despite the involvement of the Customs Department and its agents both in the initial detection of the drug-laden bags and the stop of the defendant, nothing in the record or the briefs indicates that the bags or any of the suspects were required to pass through U.S. Customs, or were involved in any international border-crossing. Thus, the special standards governing the constitutionality of border searches have no application here. See, e.g., United States v. Montoya de Hernandez, 473 U.S. 531, 538, 105 S.Ct. 3304, 87 L.Ed.2d 381 (1985) (explaining that the rules governing the constitutionality of searches and seizures are “qualitatively different at the international border than in the interior”).
The question presented in this appeal is narrowly drawn. There is no dispute that the defendant was “seized” for Fourth Amendment purposes when he was prevented from boarding his scheduled flight. See, e.g., United States v. Streifel, 781 F.2d 953, 960 (1st Cir.1986) (explaining that a “seizure” occurs when a reasonable person in the suspect’s position would have believed he was not free to leave). Furthermore, the government does not contend that the stop of Acosta on the jetway was supported by probable cause. It seeks, instead, to justify the detention as a reasonable investigatory stop falling within the limits of Terry v. Ohio, 392 U.S. 1, 88 S.Ct. 1868, 20 L.Ed.2d 889 (1968). The defendant, for his part, does not attempt to argue that the government lacked the requisite level of suspicion to warrant a Terry-type stop at the jetway. He asserts, rather, that both the mode and duration of his detention were unreasonable in the circumstances, exceeded the parameters of Terry, and constituted a de facto arrest unsupported by probable cause. The district court sided with the government, ruling that Acosta’s detention was a lawful Terry stop.
B.
In assessing the district court’s determination, we review its findings of fact for *14dear error, but we review de novo its conclusions of law and its ultimate rulings on the constitutionality of the government’s conduct. See United States v. Young, 105 F.3d 1, 5 (1st Cir.1997). We bear in mind, too, that where a defendant challenges the constitutionality of a warrantless seizure undertaken on the basis of suspicion falling short of probable cause, the government bears the burden of proving that the seizure was sufficiently limited in its nature and duration to satisfy the conditions of a Terry-type investigative stop. See Florida v. Royer, 460 U.S. 491, 500, 103 S.Ct. 1319, 75 L.Ed.2d 229 (1983) (plurality opinion); United States v. Johnson, 63 F.3d 242, 245 (3d Cir.1995), cert. denied, 518 U.S. 1007, 116 S.Ct. 2528, 135 L.Ed.2d 1052 (1996); United States v. Perdue, 8 F.3d 1455, 1462 (10th Cir.1993).
C.
Before the Supreme Court’s decision in Terry, all “seizures” of persons were analyzed as “arrests,” which could be constitutionally justified only when the government had probable cause to believe that the seized person had committed or was committing a crime. See Dunaway v. New York, 442 U.S. 200, 208-09, 99 S.Ct. 2248, 60 L.Ed.2d 824 (1979); United States v. Quinn, 815 F.2d 153, 156 (1st Cir.1987); Wayne R. LaFave, Search and Seizure § 5.1(a), at 9 (3d ed.1996). In Terry, the Court gave effect to the notion that some types of encounters between the police and citizens—such as brief detainments in the nature of a “stop and frisk”—could constitute “seizures” for Fourth Amendment purposes, yet be sufficiently limited in their intrusiveness to fall outside the traditional understanding of an “arrest.” See Dunaway, 442 U.S. at 208-09, 99 S.Ct. 2248. The Court held that these limited types of seizures, by virtue of their low level of intrusiveness relative to the important law enforcement purposes they served, could be constitutionally justified on a level of suspicion falling short of probable cause. See id. at 209, 99 S.Ct. 2248; Terry, 392 U.S. at 27, 88 S.Ct. 1868; LaFave, supra, § 5.1(a), at 9.
Over time, the Terry doctrine has developed into an extremely elastic rule with a broad range of application. In its modern adaptation, the doctrine provides that “based merely on a reasonable and articulable suspicion, a police officer may make a brief stop or ‘seizure’ of an individual to investigate suspected past or present criminal activity.” United States v. McCarthy, 77 F.3d 522, 529 (1st Cir.1996), cert. denied, — U.S. -, 117 S.Ct. 771, 136 L.Ed.2d 717 (1997). Such a seizure will be upheld as constitutionally permissible so long as it was “justified at its inception, and, if so, ... the action taken was reasonably related in scope to the circumstances which justified the interference.” Young, 105 F.3d at 6.
This general test of reasonableness is obviously expansive in its compass. As a doctrinal matter, however, the test presupposes that the seizure under scrutiny was, on the whole, a less intrusive measure than an actual arrest. In other words, a warrantless seizure supported by less than probable cause necessarily falls below the applicable threshold of reasonableness if the seizure was the functional equivalent of an arrest. See, e.g., Quinn, 815 F.2d at 156 (stating that detentions “which though not technical, formal arrests are the ‘equivalent of an arrest’ ... require probable cause”). This must be so because Terry was intended to carve out an exception to the probable cause requirement only for relatively brief, non-arrest detentions; plainly, a seizure that is, de facto, tantamount to an arrest cannot fit within that exception. See id.; see also United States v. Zapata, 18 F.3d 971, 975 (1st Cir.1994).
There is no “litmus-paper test,” however, to determine whether any particular mode of detention amounted to a de facto arrest. Royer, 460 U.S. at 506, 103 S.Ct. 1319 (plurality opinion); see also Zapata, 18 F.3d at 975 (no “scientifically precise formula”); Quinn, 815 F.2d at 156 (no “mechanical checklist”). It is often said that an investigatory stop constitutes a defacto arrest “when ‘a reasonable man in the suspect’s position would have understood his situation,’ in the circumstances then obtaining, to be tantamount to being under arrest.” Zapata, 18 F.3d at 975 (quoting Berkemer v. McCarty, 468 U.S. 420, 441, 104 S.Ct. 3138, 82 L.Ed.2d *15317 (1984)); see also Young, 105 F.3d at 7; Quinn, 815 F.2d at 157; LaFave, supra, § 5.1(a), at 9. But in a typical borderline case, e.g., one in which the detention at issue has one or two arrest-like features but otherwise is arguably consistent with a Terry stop, it will not be obvious just how the detention at issue ought reasonably to have been perceived; indeed, this will be the central point of contention. Thus, in such a case — that is, where the detention is distinguishable from, yet has some features normally associated with, an arrest — the analysis must revert to an examination of whether the particular arrest-like measures implemented can nevertheless be reconciled with the limited nature of a Terry-type stop. This assessment requires a fact-specific inquiry into whether the measures used were reasonable in light of the circumstances that prompted the stop or that developed during its course. See Young, 105 F.3d at 8 (“Above all else, our cases in this area evince the fact specific nature of the inquiry.”); Washington v. Lambert, 98 F.3d 1181, 1185 (9th Cir.1996) (suggesting that the same police actions can constitute a de facto arrest in some circumstances but not in others).
D.
It can hardly be doubted that the initial stop and subsequent detention of Acosta featured several characteristics ordinarily associated with an arrest: he was prevented from boarding his plane, placed in handcuffs, involuntarily transported (in restraints) to an official holding area some distance from the place of the original stop, confined to a small interrogation room and kept there under observation for more than a momentary period; yet he was never informed how long he would be detained nor told that he was not under arrest. See United States v. Glenna, 878 F.2d 967, 972 (7th Cir.1989) (“[H]and-cuffs are restraints on movement normally associated with arrest. Clearly, the thought of allowing police officers to handcuff persons where probable cause to arrest is lacking is a troubling one.”); McCarthy, 77 F.3d at 532 (noting, in finding that detention was a permissible Terry stop, that the suspect “was never handcuffed” and was told he was not under arrest); United States v. Berry, 670 F.2d 583, 598 (5th Cir.1982) (en bane) (suggesting that bringing a suspect to a police office effects “a marked increase in the coercive nature” of a detention). Furthermore, Acosta’s detention caused him to miss his flight to New York, and there is no suggestion that authorities ever communicated to Acosta any concern over disrupting his travel plans; certainly, they never gave him the choice of leaving. Cf. United States v. West, 731 F.2d 90, 91, 93-94 (1st Cir.1984) (no constitutional violation found where suspect was given choice of waiting at airport and missing his flight while officers called in a narcotics-detecting dog to sniff his suitcase, or departing on his flight but leaving his suitcase behind);5 United States v. Tavolacci, 895 F.2d 1423, 1428 (D.C.Cir.1990) (detention more likely to qualify as a Terry stop if it “did not interfere with defendant’s travel plans”).
These circumstances create, at the very least, a substantial question as to whether a reasonable person in Acosta’s position would have understood his situation as tantamount to being under arrest. But we need not rely solely on intuition to decide whether the mode of Acosta’s airport detention indeed exceeded the limits of an investigatory Terry stop. Instead, we make our determination against the background of the Supreme Court’s decision in Florida v. Royer, 460 U.S. 491, 103 S.Ct. 1319, 75 L.Ed.2d 229 (1983). There, a plurality of the Court concluded that an airport detention quite similar to Acosta’s — but in some ways less intrusive— exceeded the outer limits of a Terry-type stop and constituted a de facto anjest.6 Be*16cause of the case’s special relevance here, we discuss it in some detail.
In Royer, two narcotics detectives at Miami International Airport observed an individual, Royer, who fit a so-called “drug courier profile.” Id. at 493, 108 S.Ct. 1319. After Royer purchased a one-way ticket to New York and checked two bags, 'the detectives stopped him and asked whether he “had a ‘moment’ to speak with them”; Royer responded “yes.” Id. at 494, 103 S.Ct. 1319. On request, Royer handed the officers his airline ticket and driver’s license. When the officers pointed out to Royer that the name on his ticket did not match the name on his driver’s license, he became noticeably nervous. See id. The detectives, after identifying themselves as law enforcement officers and telling Royer that they suspected he was transporting narcotics, asked him to accompany them to a closet-sized room located in a “stewardesses’ lounge” just adjacent to the public concourse area, approximately 40 feet away from the point of their initial encounter. Id. Royer said nothing but followed the officers into the room, whereupon his bags were retrieved and brought there. See id. With Royer’s permission (or at least his passive acquiescence), one of the officers opened both of the two suitcases; a quantity of marijúana was found in each. See id. At that point— about 15 minutes from the time of his initial stop — Royer was formally arrested. See id.
In holding that Royer’s Fourth Amendment rights were violated, Justice White, writing for a plurality of the Court, stated that “[i]n the name of investigating a person who is no more than suspected of criminal activity, the police may not ... seek to verify their suspicions by means that approach the conditions of an arrest.” 460 U.S. at 499,103 S.Ct. 1319. Reviewing the salient features of the investigatory seizure at issue, the plurality opinion summarized the facts as follows:
[The officers] requested [Royer] to accompany them to the police room. Royer went them. He found himself in a small — a large closet — equipped with a and two chairs.... What had begun a consensual inquiry in a public place escalated into an investigatory proce-in a police interrogation room, where police, unsatisfied with previous explanations, sought to confirm their suspicions. officers had Royer’s ticket, they had identification, and they had seized his luggage. Royer was never informed that was free to board his plane if he so chose, and he reasonably believed that he being detained.
Id. at 502-03, 103 S.Ct. 1319. Based on these facts, the plurality concluded that, “[a]s a practical matter, Royer was under arrest,” id. at 503,103 S.Ct. 1319, and that his detention therefore exceeded the limits of a Terry stop, id. at 507, 103 S.Ct. 1319.
There is little to distinguish Acosta’s ease from Royer. The governmental objective here, as in Royer, was to investigate a possible drug-trafficking offense — more specifically, to confirm or dispel a suspicion that Acosta had a connection with certain luggage believed to contain narcotics (or with the persons to whom the bags were registered). If anything, though, the mode of Acosta’s detention was more intrusive than Royer’s: Acosta’s stop did not “beg[i]n as a consensual encounter,” 460 U.S. at 503, 103 S.Ct. 1319; he was handcuffed, involuntarily taken to a secured area (the “customs enclosure area”) much farther than 40 feet from the place of his initial stop; and he was confined to an official interrogation room (rather than a “stewardesses’ lounge”), from which the government concedes he was not free to leave. Moreover, the total time of Acosta’s detention (up to the time of the formal arrest) was nearly twice as long as Royer’s.
The government makes no suggestion that Royer is no longer good law, nor does it deny the similarities between that case and this one. Instead, the government asks us to *17focus upon the Royer plurality’s statement that “[t]here are undoubtedly reasons of safety and security that would justify moving a suspect from one location to another during an investigatory detention, such as from an airport concourse to a more private area.” 460 U.S. at 604, 103 S.Ct. 1319. Parrotting this language, the government asserts in its brief, with little elaboration, that “security reasons prompted the officers not to interview [Acosta] at the jetway and to transfer the site of the encounter ... to the interrogation room.”
The difficulty, however, is that the government has utterly failed to identify specific facts supporting its invocation of “security reasons” as justification for the movement of Acosta to the interrogation room.7 It may well be true, of course, that it was indeed safer for authorities to question Acosta in an interrogation room than, for example, on the jetway. Common sense suggests that transporting a suspect to an interrogation room (or for that matter, locking him in a holding cell) will always incrementally enhance the safety and security of law enforcement officers and the public. In this sense, there will always exist “security reasons” to move the subject of a Terry-type stop to a confined area pending investigation. But if this kind of incremental increase in security were sufficient to warrant the involuntary movement of a suspect to an official holding area, then such a measure would be justified in every Terry-type investigatory stop. That result surely is not within the contemplation of Royer. See LaFave, supra, § 9.2(g), at 75-76.
Whatever might qualify as “reasons of safety and security” sufficient to “justify moving a suspect from one location to another during an investigatory detention” (such as from the place of the initial stop to an interrogation room), Royer, 460 U.S. at 504, 103 S.Ct. 1319 (plurality), the requisite justification cannot rest upon bald assertions, such as those offered by the government here, that law enforcement officers were in fact prompted to act on such reasons. The government must point to some specific fact or circumstance that could have permitted law enforcement officers reasonably to believe that relocating the suspect to a detention room was necessary to effectuate a safe investigation. See Royer, 460 U.S. at 505-06, 103 S.Ct. 1319 (plurality). It has failed to do so.
Our own independent examination of the record reveals very little that would aid the government’s position. In fact, a reading of the suppression-hearing testimony of the customs inspector who initially stopped Acosta only underscores the absence of specific circumstances that might have supported a belief that the suspects’ relocation to the detention area was necessary for reasons of safety or security. For example, when the customs inspector was asked by the prosecutor to explain the instructions he had received before attempting to intercept the suspects at the gate area, he testified he was told by his supervisor “[t]o identify [the suspects] if they boarded and—and to bring them back to the [customs] enclosure,” whereupon, according to “standard operating procedure,” the suspects were to be “turned ... over to [the] DEA.”8 Far from pointing to actual circum*18stances that might have justified a belief that an investigatory stop could not have been conducted safely without removing the suspects from the area of the jetway, this testimony suggests that the decision ■ to move Acosta and the other suspects to the interrogation room was essentially predetermined, undertaken simply as a matter of routine for the purpose of facilitating a transfer of “custody” from the customs agents to the DEA.9
In all events, it is evident that here, as in Royer, “[t]he record does not reflect any facts which would support a finding that the legitimate law enforcement purposes which justified the detention in the first instance were furthered by removing” the defendant to an interrogation room in the so-called customs enclosure area. 460 U.S. at 505, 103 S.Ct. 1319.
E.
The fact that Acosta was placed in handcuffs before being taken to the customs enclosure area further undercuts the government’s position that Acosta’s seizure fell within the scope of a Terry stop. We fully agree with the district court, and with the government, that the use pf handcuffs in the course pf an 'investigatory stop does not automatically convert the encounter into a de facto arrest. See Perdue, 8 F.3d at 1463 (collecting cases); Quinn, 815 F.2d at 157 n. 2. Police officers engaged in an otherwise lawful stop must be permitted to take measures—-including the use of handcuffs—they believe reasonably necessary to protect themselves from harm, or to safeguard the security of others. See, e.g., Michigan v. Long, 463 U.S. 1032, 1047, 103 S.Ct. 3469, 77 L.Ed.2d 1201 (1983); Washington, 98 F.3d at 1186; United States v. Stanley, 915 F.2d 54, 57 (1st Cir.1990).
But to say that the use of physical restraints is not necessarily inconsistent with a Terry-type stop does not imply that law enforcement authorities, acting on less than probable cause, may handcuff suspects as a matter of routine. See Washington, 98 F.3d at 1187 (“Under ordinary circumstances, when the police have only reasonable suspicion to make an investigatory stop, drawing weapons and using handcuffs and other restraints will violate the Fourth Amendment.”); United States v. Smith, 3 F.3d 1088, 1094 (7th Cir.1993) (seizure involving use of handcuffs may be upheld as Terry stop “in the ‘rare’ case wherein common sense and ordinary human experience convince us that an officer believed reasonably that an investigative stop could be effectuated safely only through the use of handcuffs” (citation omitted)); see also LaFave, supra, § 9.2(d), at 39, 41-42.
There is no question that the use of handcuffs, being one of the most recognizable indicia of a traditional arrest, “substantially aggravates the intrusiveness” of a putative Terry stop. Glenna, 878 F.2d at 972; see also United States v. McQuagge, 787 F.Supp. 637, 645 (E.D.Tex.1991), aff'd, United States v. Mallory, 8 F.3d 23 (5th Cir.1993) (unpublished opinion). Thus, when the government seeks to prove that an investigatory deten*19tion involving the use of handcuffs did not exceed the limits of a Terry stop, it must be able to point to some specific fact or circumstance that could have supported a reasonable belief that the use of such restraints was necessary to carry out the legitimate purposes of the stop without exposing law enforcement officers, the public, or the suspect himself to an undue risk of harm. See Washington, 98 F.3d at 1189 (describing examples of such circumstances); Glenna, 878 F.2d at 972-73; McQuagge, 787 F.Supp. at 645-46; LaFave, supra, § 9.2(d), at 40-42 (illustrating “special circumstances” in which use of handcuffs might not exceed the limits of a Terry stop).
In this case, the government identifies no such specific circumstances. There has been no suggestion that any one of the suspects was being uncooperative, belligerent, or showed any perceptible inclination to put up resistance or become violent. Nor is there evidence that any of the customs officers harbored an actual suspicion that Acosta was armed10 or otherwise presented an appreciable danger.11 The government nevertheless argues that the handcuffing of Acosta was reasonable because “the offieers[’] intervention was premised on reasonable suspicion of drug interdiction,” and Acosta, simply by virtue of being a suspected drug trafficker, “could [have] be[en] armed,” and this possibility created a risk of harm to the “many innocent bystanders” present in the general area (though presumably not in the jetway itself) where Acosta was initially stopped.12
These highly generalized statements are inadequate to establish that the handcuffing of Acosta was a reasonably measured response to actual safety concerns arising from the stop.13 Like the government’s explanation for transporting Acosta to the interrogation room, its factually unanchored justification for placing Acosta in handcuffs is generalizable to virtually every investigatory stop involving a drug suspect. To accept that purported justification here would therefore be to endorse the use of handcuffs in every investigatory stop initiated upon an articulable suspicion of drug trafficking. This we are not prepared to do. See United States v. Melendez-Garcia, 28 F.3d 1046, 1052-53 (10th Cir.1994) (acknowledging reality that “[d]rugs and guns and violence often go together” but holding that “the naked fact that drugs are suspected will not support a per se justification for use of ... handcuffs in a Terry stop”).
We álso find inadequate the government’s suggestion that the use of handcuffs may have been warranted by the need to ensure the safety of law enforcement officials and the public as the suspects were being transported to the customs detention area. First, as we have already noted, the government *20fails to specify any factual basis for its supposition that Acosta or the other two suspects might have presented an actual danger to the public or to the customs officers (who were, after all, armed).14 But more importantly, as discussed above, the government has failed to demonstrate that Acosta’s transportation to (and subsequent detention in) the customs enclosure area was itself within the limits of a Terry stop. Plainly, therefore, the need to facilitate that very detention cannot provide a valid justification for the use of handcuffs; such an argument would be naked bootstrapping, at best. The government’s Terry argument requires the identification of specific circumstances that could have been thought to necessitate the use of handcuffs to carry out safely the legitimate purposes of the stop: here, investigating Acosta’s connection with the narcotics-laden suitcases. Cf. Boyer, 460 U.S. at 505, 103 S.Ct. 1319. No such circumstances have been identified.
F.
Although we have been discussing, to this point, only whether the mode of Acosta’s detention was consistent with a Terry type investigatory stop, we add a few words about the detention’s overall duration. There is, of course, “no rigid time limitation on Terry stops,” United States v. Sharpe, 470 U.S. 675, 685, 105 S.Ct. 1568, 84 L.Ed.2d 605 (1985), and we have previously upheld the constitutionality of investigatory stops based on reasonable suspicion lasting for as long as 75 minutes, see McCarthy, 77 F.3d at 531. Still, an investigatory detention of close to 30 minutes—particularly one that interferes with an individual’s “liberty interest in proceeding with his itinerary,” Place, 462 U.S. at 708, 103 S.Ct. 2637—is hardly a trivially intrusive affair. The question is whether the length of Acosta’s detention was reasonable, considering “ ‘the law enforcement purposes to be served by the stop ... and whether the police diligently pursued a means of investigation that was likely to confirm or dispel their suspicions quickly, during which time it was necessary to detain the defendant.’ ” McCarthy, 77 F.3d at 530 (quoting Shaipe, 470 U.S. at 686, 105 S.Ct. 1568).
The government’s stated purpose for stopping Acosta was to investigate whether he had any connection with or knowledge of the narcotics-laden suitcases that had been checked on the New York-bound flight that Acosta was about to board. Yet, conspicuously absent from the government’s presentation is any description of a single investigatory action that was being pursued by law enforcement authorities, while Acosta was being detained, to “confirm or dispel” their suspicion that Acosta was involved with the suitcases.15 In fact, the government fails to provide us with any insight at all into what the customs office, the DEA, or any other law enforcement body was doing during the time that Acosta was being detained on the jetway, transported to the customs area, and left to wait in an interrogation room. We have thus been provided with no basis in the record to conclude that the responsible au*21thorities were pursuing any active investigation, let alone were “diligent” in doing so, to “confirm or dispel” their suspicions concerning Acosta. There has been no suggestion, furthermore, that Acosta was uncooperative or otherwise was himself partly to blame for the extended length of his detention. Thus, unlike in McCarthy, where the record supported a finding that the suspect’s detention became prolonged in spite of the diligent efforts of police officers, see 77 F.3d at 531—32, the record before us is devoid of any factual basis on which we could make a similar finding.
G.
We emphasize, as we have already said, that there are no bright-line rules to determine whether an investigatory stop initiated on the basis of reasonable suspicion falls within the ambit of Terry. Thus, even though several aspects of Acosta’s stop and detention (particularly when viewed in combination) appear to mirror characteristics of a traditional arrest, these features do not automatically convert the episode into a de facto arrest. The presence of these arrest-like features does, however, require the government to identify specific facts or circumstances which could have led the acting law enforcement officers reasonably to believe that the use of such measures was required to effectuate safely the contemplated investigation. The government has not done so. Similarly, while there are surely a variety of circumstances that could permit a finding of constitutional reasonableness with respect to an investigatory stop of a duration comparable to or exceeding that of Acosta, the government is required at least to identify specifically what those circumstances might be. Again, it has not done so. The government has thus failed to meet its burden of demonstrating that Acosta’s seizure was sufficiently limited in its intrusiveness to have been constitutionally permissible in the absence of probable cause. In so finding, we do not decide whether the government’s failure to provide adequate justification for any single aspect of Acosta’s seizure, considered in isolation, would have yielded a similar conclusion. But given the absence of basis in the record to support a finding of constitutional reasonableness as to any one of the challenged aspects of the defendant’s warrantless seizure, we have little choice but to hold that the stop, handcuffing, and ensuing detention at issue amounted to an unlawful de facto arrest.
III.
Our holding that the defendant’s stop and detention exceeded the limits of a lawful Terry stop does not completely resolve this case. While the conclusions we have reached require us to reverse the district court’s ruling that Acosta’s constitutional rights were not violated, those conclusions do not determine the scope of the suppression order (if any) to be entered.16 Because the court below denied the defendant’s motion to suppress, it had no occasion to make any findings as to the particular items of evidence that might constitute the “fruits” of any violation of Acosta’s rights. But the question whether the evidence the defendant seeks to suppress constitutes the fruit of the poisonous tree or has been sufficiently “ ‘purged of the primary taint’” caused by the illegal seizure “depends primarily upon weighing the facts in the particular case, ... and is thus a matter especially suitable for resolution by the district court” in the first instance. United States v. Finucan, 708 F.2d 838, 843 (1st Cir.1983) (quoting Wong Sun v. United States, 371 U.S. 471, 488, 83 S.Ct. 407, 9 L.Ed.2d 441 (1963) (internal citation omitted)). We must, therefore, remand this matter to the district court for specific findings identifying which items of evidence, if any, can properly be deemed the fruits of Acosta’s illegal seizure.
We think it fair to note, however, that based on the record currently before us, we can see no reason why the baggage claim tickets Acosta tried to swallow ought not be found to constitute the fruits of his illegal detention. Cf. United States v. King, 990 F.2d 1552, 1563-64 (10th Cir.1993) (finding that drugs defendant attempted to discard *22during illegal arrest were illegal fruits); La-Fave, supra, § 2.6(b), at 584-85 (“[W]here a person has disposed of property in response to a police effort to make an illegal seizure ... courts have not hesitated to hold that property inadmissible.” (footnotes omitted)). On the other hand, the status of the statements Acosta made to authorities after receiving his Miranda warnings appears to us to present a closer question, one as to which we express no view at this time. See Brown v. Illinois, 422 U.S. 590, 95 S.Ct. 2254, 45 L.Ed.2d 416 (1975) (setting forth the relevant analysis); United States v. Ramos, 42 F.3d 1160, 1164 (8th Cir.1994) (explaining the holding of Brown), cert. denied, 514 U.S. 1134, 115 S.Ct. 2015, 131 L.Ed.2d 1013 (1995); United States v. Butts, 704 F.2d 701, 704-05 (3d Cir.1983) (same).
IV.
For the reasons stated, the district court’s denial of the defendant’s motion to suppress is reversed, the judgment of conviction is vacated, and this case is remanded for further proceedings consistent with this opinion. The defendant shall be permitted to withdraw his plea of guilty, pursuant to the terms of his conditional plea agreement. Cf. United States v. Infante-Ruiz, 13 F.3d 498, 505 (1st Cir.1994).
So Ordered.
. As stated in the district court's opinion, the "jetway" refers to the tunnel-like passageway leading from the airport terminal to the airplane.
. The parties stipulated for purposes of obtaining a ruling on the defendant’s motion to suppress that Acosta's handcuffs were removed once he was brought to the customs enclosure area. However, one of the customs inspectors testified at the suppression hearing that, although he did not see what happened to Acosta, the suspect he happened to be watching was actually handcuffed to his chair. After Acosta's motion to suppress was denied and he entered his conditional plea of guilty, defense counsel stated for the record (at the end of the plea hearing) that Acosta had stipulated that his handcuffs were removed only "for the purposes of the suppression hearing.” The intended effect of this qualifying statement by counsel is not entirely clear. For purposes of this appeal, however, the parties appear to abide by their original stipulation of facts. Accordingly, we assume that Acosta's handcuffs were in fact removed after he was patted down inside the customs enclosure area.
. There is no evidence in the record indicating whether the rooms were locked, but counsel for the government represented to the district court at the suppression hearing that the door to Acosta’s interrogation room was left open. At oral argument on appeal, however, government counsel stated it was not clear from the record whether the door was open, closed, or locked, but that in any event, Acosta certainly would not have been permitted to leave the room had he attempted to do so.
. The other two suspects were released.
. The suspect in West ultimately chose to leave without his luggage. While he was en route to his destination, a canine unit detected drugs in the suitcase, a warrant was obtained, and a search of the suitcase turned up a quantity of drugs. Federal authorities at the suspect’s destination city were so notified, and the suspect was arrested there. See 731 F.2d at 91.
. The plurality opinion in Royer was authored by Justice White and joined by three other justices. Justice Brennan concurred in the result but did not join Justice White’s opinion, because in Justice Brennan's view, the initial stop of the defendant was unsupported by reasonable suspicion and hence was illegal from the outset; for this reason, Justice Brennan saw no need to address *16whether the stop was conducted in such a manner as to constitute a de facto arrest. See 460 U.S. at 509, 103 S.Ct. 1319 (Brennan, J., concurring). However, Justice Brennan did state explicitly in his concurring opinion that he agreed with the plurality's conclusion that, assuming that the initial stop was legal, the detention of the suspect of a Terry ‘investigative stop.’ ” Id. Thus, although technically speaking, Justice White's opinion was supported by four members of the Court, five members supported his main conclusion — the conclusion relevant to this case — that the stop at issue constituted a de facto arrest.
. Our dissenting colleague emphasizes that Acosta's initial stop occurred during the airport’s "rush hour," but there is no evidence that the jetway on which Acosta was stopped was itself even open to public traffic after the boarding of the departing flight had concluded. As far as the record shows, it was not the jetway—the place of the initial stop—that was affected by the "rush hour” at all; the crowded area of the airport was, instead, the public concourse through which the suspects were taken en route to the customs enclosure area. Thus, the fact that the stop occurred during "rush hour" does not provide a persuasive justification for moving Acosta from the place of the initial stop to the detention area.
. Consistent with this testimony, the parties’ stipulated statement of facts recites that once the suspects had been brought to the detention area, they were in fact "transferred to the custody of the DEA.” But we should note that there is no independent evidence in the record to corroborate the customs officer's testimony about the "standard operating procedures” of the customs department, and the district court made no findings relating thereto. More importantly, the government has not argued'—and there is nothing in the record that would support the proposition— that the actions of the customs officers were constitutionally reasonable by virtue of the fact that the "standard” procedures they were osten*18sibly following were themselves reasonable or otherwise justified as a whole.
. In respect to these facts, Acosta's detention is arguably similar to the one characterized as a de facto arrest in Dunaway v. New York, 442 U.S. 200, 99 S.Ct. 2248, 60 L.Ed.2d 824 (1979). There, the police, acting without probable cause, had "pick[ed] up" the defendant at a neighbor's house, "br[ought] him in" to police headquarters, and then placed him in an interrogation room for questioning. Id. at 207, 99 S.Ct. 2248. The Court found that this investigatory detention "was in important respects indistinguishable from a traditional arrest” and held that it could not be justified as a Terry stop. It noted that “any 'exception that could cover a seizure as intrusive as that in this case would threaten to swallow the general rule that Fourth Amendment seizurcs are 'reasonable' only if based on probable cause.” Id. at 213, 99 S.Ct. 2248. The Court cautioned that "detention for custodial interrogation—regardless of its label—intrudes so severely on interests protected by the Fourth Amendment as necessarily to trigger the traditional safeguards against illegal arrest.” Id. at 219, 99 S.Ct. 2248. To the extent that the record in this case supports an inference that Acosta was brought to the customs detention area and placed in an interrogation room in order to effect a transfer of "custody" to and permit questioning by the DEA, the rule of Dunaway arguably comes into play. Cf. United States v. Codd, 956 F.2d 1109, 1111 (11th Cir.1992) (holding that two and one-half hour detention at airport police office was analogous to the de facto arrest in Dunaway).
. As to whether the officers could reasonably have suspected that Acosta was actually armed, it is relevant to observe that Acosta had successfully passed through the airport's metal detectors by the time he was stopped. Cf. United States v. Kelly, 913 F.2d 261, 264 (6th Cir.1990) (noting that airport security devices reduce likelihood that airplane passengers will be armed).
. Both the government and the district court have noted (as has the dissent) that one of the suspects other than Acosta happened to be a very large man, weighing over 300 pounds. But even if this fact might have justified restraining that particular individual (an issue we do not consider), we fail to see how it could plausibly be cited as a legitimate reason for placing handcuffs on Acosta.
. The dissent’s analysis relies heavily on the assumption that the customs inspectors who stopped Acosta knew "to a practical certainty” that “a substantial quantity of drugs was being transported by one or more passengers about to board the departing American Airlines flight.” The government has not asserted in this appeal, however, nor has it pointed to any evidence in the record to suggest, that the customs inspectors had any information or knowledge about the quantity of drugs contained in the suspect luggage at the time of Acosta's stop and detention. The government’s brief states only that a canine unit detected the presence of some quantity of drugs in four suitcases, and that, at some unspecified time, the two suitcases that matched the claim tickets in Acosta’s possession were found to contain 15 kilograms of cocaine each.
. We note that the officers did not frisk Acosta until after he had been brought to the customs enclosure area, rather than immediately after he was handcuffed and before he was led out of the jetway into the airport concourse. Cf. LaFave, supra, § 9.2(d), at 42 (suggesting that if handcuffs are used in a Terry stop based on a suspicion that the suspect is armed, the restraints normally must be removed following a pat-down revealing the absence of weapons).
. The customs inspector who testified at the suppression hearing stated initially that the suspects were handcuffed “because we were detaining them for investigation purposes and to safeguard them and us and the ... public.” But upon further prompting by the prosecutor, the inspector explained that handcuffing was considered "S.O.P.”—standard operating procedure— in the customs office. On cross-examination, the officer admitted that the “number one" reason for handcuffing the suspects before bringing them back to the detention area was to comply with standard operating procedure for a “customs detention,” and he added that “if [the suspects] did get away we'd have actually [sic] dereliction of duty." The testifying officer's stated reliance on "standard operating procedure” tends to suggest that the decision to use handcuffs did not depend upon the presence of specific circumstances that (objectively) might have necessitated their use. The dissent asserts that "the defense has never challenged” the purported "SOP,” but the defendant surely is not required to do so in order to assert that his stop and detention amounted to a de facto arrest. It is the government that bears the burden of demonstrating that Acosta’s stop fell within the scope of Terry. The government has not attempted to carry its burden in this case by arguing that the customs officers were following standard procedures, let alone that those procedures themselves could constitutionally be justified.
. As stated in the parties’ stipulation of facts, the authorities did not even ask Acosta any questions until after he attempted to swallow the incriminating baggage claim tickets that evidently had been in his possession (which, curiously, he had not previously been asked to produce).
. The illegality of Acosta’s seizure does not bar his prosecution or conviction. United States v. Crews, 445 U.S. 463, 474, 100 S.Ct. 1244, 63 L.Ed.2d 537 (1980).