the INS inspector, and thereafter, if the inspector determines that the passenger is a citizen or is legally in the United States, the passenger must remain isolated from the general public until departure of the aircraft.
This procedure is patently distinguishable from Martinez-Fuerte in two important ways, only one of which is recognized as such by the majority. The first difference lays in the seizure during interrogation of the passenger’s ticket, even absent what the majority refers to as “some hint” that the passenger is illegally within the United States. Ante at 908. Of course more than a mere “hint” is required for such a seizure, Florida v. Royer, 460 U.S. 491, 103 S.Ct. 1319, 75 L.Ed.2d 229 (1983), Brown v. Texas, 443 U.S. 47, 99 S.Ct. 2637, 61 L.Ed.2d 357 (1979), but be that as it may, the fact remains that this seizure is not a separate incident in the passenger’s stop and interrogation but rather an integral part of the same. Its obviously intended purpose is to prevent freedom of action by the subject. Royer, 461 U.S. at 501-02, 103 S.Ct. at 1326-27. The excision of this intrinsic act, for “analytic purposes” or otherwise, simply runs contrary not only to reason, but more importantly, to the record which unequivocably reveals that “[t]he agents ... receive instructions to take the tickets of passengers while questioning them,” López, 649 F.Supp. at 857 (emphasis supplied).
The second important distinguishing feature found in this case, not present in Martinez-Fuerte, is the isolation or quarantining of the passengers from the general population, once they have “passed” the INS’s “protocol.” The purpose of this imposed segregation is, of course, obvious; it is an effective means of keeping uncontaminated those passengers who have passed INS’s “protocol.” But I assume that no one would in this day and age suggest, merely because a law enforcement tool is effective, that it is automatically constitutional. I do not see how such an additional restriction, even if considered separately, and much less if weighted in the context of this entire procedure, can be valid.
The approval of such a restriction can only stem from an implicit acceptance that a border, “secondary” or otherwise, exists between Puerto Rico and the mainland, allowing INS to do between San Juan and the mainland what it normally could only do to passengers crossing an international border of the United States; that is, isolate them until they have entered or detain them upon reasonable suspicion of a crime being committed. United States v. Montoya de Hernández, 473 U.S. 531, 105 S.Ct. 3304, 87 L.Ed.2d 381 (1985). Yet this clearly is not permissible here, as no border exists between Puerto Rico and the mainland for immigration purposes, and legal residents of Puerto Rico can freely travel to the mainland without any restriction. Balzac v. People, 258 U.S. 298, 42 S.Ct. 343, 66 L.Ed. 627 (1922); Savoretti v. Voiler, 214 F.2d 425, 427-28 (5th Cir.1954) (no “entry” for immigration purpose when resident alien returns to mainland from Puerto Rico); 8 U.S.C. § 1101(36), (38) (1982) (Puerto Rico is within the United States for immigration purposes). See also Torres v. Puerto Rico, 442 U.S. 465, 472-73, 99 S.Ct. 2425, 2430-31, 61 L.Ed.2d 1 (1979) (no “intermediate border” exists between Puerto Rico and United States); cf. Gonzales v. Williams, 192 U.S. 1, 24 S.Ct. 177, 48 L.Ed. 317 (1904).
The majority agrees that no “secondary” border exists, ante at 901-02, yet permits a procedure, quarantine, which is only valid, even in a criminal or public health context, when crossing international borders if a “reasonable suspicion” standard is met. United States v. Montoya de Hernández, supra. See 19 U.S.C. § 1582. In fact, the INS’s “protocol” is more intrusive of the passengers’ freedom than when crossing an international border. Not only is there a stop and seizure during the interrogation regarding citizenship, but even after the passenger “passes” this gauntlet, his freedom is further curtailed by his having to remain “separate and apart from the general public.” 8 C.F.R. § 235(a) (1986).
An alternative ground to explain this situation may be the possible misconception that INS can constitutionally do in Puerto Rico what it cannot do in the States of the