The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
That searches made at the border, pursuant to the longstanding right of the sovereign to protect itself by stopping and examining persons and property crossing into this country, are reasonable simply by virtue of the fact that they occur at the border, should, by now, require no extended demonstration.1 Authorized by the First Congress,2 the customs search in these circumstances requires no warrant, no probable cause, not even the showing of some degree of suspicion that accompanies even investigatory stops.3 Moreover, although prolonged detention of travelers beyond the routine customs search and inspection must be justified by the Terry standard of reasonable suspicion having a particularized and objective basis, Terry protections as to the length and intrusiveness of the search do not apply.4 Motor vehicles may be searched at the border, even to the extent of removing, disassembling, and reassembling the fuel tank.5
Inland stoppings and searches in areas away from the borders are a different matter altogether. Thus, in Almeida-Sanchez v. United States,6 the Court held that a warrantless stop and search of defendant’s automobile on a highway some 20 miles from the border by a roving patrol lacking probable cause to believe that the vehicle contained unlawfully present aliens violated the Fourth Amendment. Similarly, the Court invalidated an automobile search at a fixed checkpoint well removed from the border; while agreeing that a fixed checkpoint probably gave motorists less cause for alarm than did roving patrols, the Court nonetheless held that the invasion of privacy entailed in a search was just as intrusive and must be justified by a showing of probable cause or consent.7 On the other hand, when motorists are briefly stopped, not for purposes of a search but in order that officers may inquire into their residence status, either by asking a few questions or by checking papers, different results are achieved, so long as the stops are not truly random. Roving patrols may stop vehicles for purposes of a brief inquiry, provided officers are
aware of specific articulable facts, together with rational inferences from those facts, that reasonably warrant suspicion that an automobile contains unlawfully present aliens; in such a case the interference with Fourth Amendment rights is
modest and the law enforcement interests served are significant.8 Fixed checkpoints provide additional safeguards; here officers may halt all vehicles briefly in order to question occupants even in the absence of any reasonable suspicion that the particular vehicle contains unlawfully present aliens.9