Order Code RL31826
Report for Congress
Received through the CRS Web
Protecting Our Perimeter:
“Border Searches” under
the Fourth Amendment
Updated May 14, 2003
Stephen R. Viña
Legislative Attorney
American Law Division
Congressional Research Service ˜ The Library of Congress

Protecting our Perimeter: “Border Searches”
under the Fourth Amendment
Summary
Many border security initiatives were developed after the events of September
11, 2001. Because security initiatives often maintain a search and seizure
component, Fourth Amendment implications may arise. The Fourth Amendment
establishes that a search or seizure conducted by a governmental agent must be
reasonable, and that probable cause support any judicially granted warrant. An
invalid “search” is an infringement of an expectation of privacy that society is
prepared to consider reasonable. A “seizure” of a person occurs when a government
official makes an individual reasonably believe that he or she is not at liberty to
ignore the government’s presence in view of all the circumstances surrounding the
incident. The Court has interpreted the Fourth Amendment to include a presumptive
warrant requirement on all searches and seizures conducted by the government, and
has ruled that any violations of this standard will result in the suppression of any
information derived therefrom. The Court, however, has also recognized situations
that render the obtainment of a warrant impractical or against the public’s interest,
and has accordingly crafted various exceptions to the warrant and probable cause
requirements of the Fourth Amendment.
Few exceptions to the presumptive warrant and probable cause requirements are
more firmly rooted than the “border search” exception. Pursuant to the right of the
United States to protect itself by stopping and examining persons and property
crossing into the country, routine border searches are reasonable simply by virtue of
the fact that they occur at the border. Courts have recognized two different legal
concepts for authorizing border searches away from the actual physical border: (1)
searches at the functional equivalent of the border; and (2) extended border searches.
Courts have determined that border searches usually fall into two categories —
routine and nonroutine. Generally, the distinction between “routine” and
“nonroutine” turns on the level of intrusiveness. Routine border searches are usually
very limited intrusions into a person’s privacy and require no suspicion of illegal
activity to be upheld by a court. Nonroutine border searches must generally be
supported by “reasonable suspicion” and can include intrusive searches of inanimate
objects, prolonged detentions, strip searches, body cavity searches, and x-ray
searches.
This report addresses the scope of the government’s authority to search and
seize individuals at the border pursuant to the constitutional framework that
encompasses the border search exception to the warrant and probable cause
requirements of the Fourth Amendment. This report also describes the varying levels
of suspicion generally associated with each type of border search as interpreted by
the courts. This report does not address interior searches and seizures performed by
immigration personnel since they are not traditional “border searches” in the Court’s
view. This report will be updated as warranted.

Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
The Fourth Amendment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Seizure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Border Searches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Functional Equivalent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Extended Border Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
At Sea . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Types of Searches and Seizures at the Border . . . . . . . . . . . . . . . . . . . . . . . . 9
Routine Searches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Nonroutine Searches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Searches of Inanimate Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Prolonged Detentions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Strip Searches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Body Cavity Searches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
X-Ray Searches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Protecting our Perimeter: “Border Searches”
under the Fourth Amendment
Introduction
United States border policy has reflected a longstanding goal of balancing
legitimate cross-border commerce and travel with the right of the sovereign to protect
itself from terrorist activities, illegal immigrants, and contraband. After the fatal
events of September 11, 2001, border security received considerable attention from
the White House and the Congress and many new security initiatives were developed.
The judiciary also noted that the events of September 11 emphasized a heightened
need to conduct searches and more thorough inspections at our borders.1 Because
security initiatives often contain a search and seizure component, Fourth Amendment
implications may arise. The Fourth Amendment establishes that a search or seizure
conducted by a governmental agent must be reasonable, and that probable cause
support any judicially granted warrant. Although the Supreme Court has interpreted
this language as imposing a presumptive warrant requirement on all searches and
seizures conducted by governmental authority, the Court has recognized exceptions
to the warrant and probable cause requirements of the Fourth Amendment.
Few exceptions to the usual Fourth Amendment requirements are more firmly
rooted in the history of the United States than the “border search” exception.
Pursuant to the right of the sovereign to protect itself by stopping and examining
persons and property crossing into the country, routine border searches are reasonable
simply by virtue of the fact that they occur at the border. Routine searches are
usually very limited intrusions into a person’s privacy, generally consist of a patdown
or the emptying of pockets, and do not require suspicion of criminal activity to be
conducted. Upon a “reasonable suspicion” of smuggling or other illegal activity,
government officials may generally conduct a nonroutine border search. Nonroutine
searches include intrusive searches of inanimate objects, prolonged detentions, strip
searches, body cavity searches, and x-ray searches. Although there is support to
require a stronger suspicion requirement for some nonroutine border searches, courts
have interpreted Supreme Court precedent as warning against the development of
multiple gradations of suspicion in the context of nonroutine border searches.
This report addresses the scope of the government’s authority to search and
seize individuals at the border pursuant to the constitutional framework that
encompasses the border search exception to the warrant and probable cause
requirements of the Fourth Amendment. Initially, this report analyzes the historical
development of the Fourth Amendment and its “border search” exception. It then
1 United States v. Teng Yang, 286 F.3d 940, 944 n.1 (7th Cir. 2002); Bradley v. United States,
299 F.3d 197, 202 (3d Cir. 2002); Chen Yun Gao v. Ashcroft, 299 F.3d 266, 281 (2002)
(Greenberg, J., dissenting).

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describes the varying levels of suspicion generally associated with each type of
search as interpreted by the courts. Although related, this report does not address the
various types of interior searches and seizures performed by immigration personnel.
The Fourth Amendment
The Fourth Amendment provides: “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.”2 It establishes, in essence, that a search or seizure
conducted by a government agent must be reasonable, and that probable cause must
support any judicially granted warrant.3 In general, the purpose of the Fourth
Amendment is to protect the people of the United States against arbitrary action by
their own government, not to restrain the actions of the federal government against
aliens outside of United States territory.4
Initially, the Supreme Court interpreted the “reasonableness” standard of the
Fourth Amendment as imposing a presumptive warrant requirement, stating that
“searches conducted outside the judicial process without prior approval by judge or
magistrate are per se unreasonable under the Fourth Amendment - subject only to a
few specifically established and well delineated exceptions.”5 The Court, however,
has wavered from this approach, determining that “a warrant is not required to
establish the reasonableness of all government searches; and when a warrant is not
required . . . probable cause is not invariably required either.”6 Traditionally, the
warrant requirement in the criminal setting has been viewed as a protective measure,
placing the authority to issue a warrant with a “neutral and detached” judicial officer
who can assess whether the police have probable cause to make an arrest, to conduct
a search, or to seize materials.7 In instances where the interests of the public
outweigh those of private individuals, however, the Court has recognized
2 U.S. Const., Amend. IV.
3 The Supreme Court has interpreted probable cause to mean “a fair probability that
contraband or evidence of a crime will be found in a particular place.” Illinois v. Gates, 462
U.S. 213, 238 (1983).
4 United States v. Verdugo-Urquidez, 494 U.S. 259, 266 (1990) (Fourth Amendment not
applicable to search in Mexico of Mexican citizen’s home). Immigration laws have long
made a distinction between those aliens who have come to our shores seeking admission
and those who are within the U.S. after an entry, irrespective of its legality. In the latter
instance, the Court has recognized additional rights and privileges not extended to those in
the former category, who are merely “on the threshold of initial entry.” Leng May Ma v.
Barber
, 357 U.S. 185, 187 (1958) (articulating the “entry fiction” doctrine).
5 Katz v. United Sates, 389 U.S. 347, 357 (1967).
6 Vernonia School Dist. 47J v. Acton, 515 U.S. 646, 653 (1995). Interpreted literally, the
Fourth Amendment requires neither a warrant for each search or seizure, nor probable cause
to support a search or seizure.
7 See Coolidge v. New Hampshire, 403 U.S. 443, 450 (1971); see also Warden v. Hayden,
387 U.S. 294, 301-02 (1967).

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“specifically established exceptions” to the warrant and probable cause requirements
of the Fourth Amendment.8
At its broadest, a Fourth Amendment analysis is a two-stage inquiry. First, was
the action of a government officer toward a person or thing sufficiently intrusive to
constitute a “search” or “seizure?”9 Second, if a “search” or “seizure” did occur,
was the intrusion “reasonable” in light of the circumstances? The “reasonableness”
of a particular government action is judged by balancing the governmental interest
which allegedly justifies the official intrusion against a person’s legitimate
expectations of privacy. Courts must consider the scope of the particular intrusion,
the manner in which it is conducted, the justification for initiating it, and the place
in which it is conducted. If a court determines that a government intrusion
constitutes a “search” or “seizure” that was not reasonable in light of the relative
weights of the government’s interest and a person’s constitutionally protected privacy
interests, it will conclude that a Fourth Amendment violation has occurred. While
a violation of the Fourth Amendment may, as a general rule, result in the suppression
of any information derived therefrom in a judicial proceeding, such a rule does not
apply to deportation proceedings.10
Seizure. In general, seizures may be of individuals or property. The Supreme
Court has described a seizure of property as “some meaningful interference with an
individual’s possessory interests in that property.”11 An individual is “seized” when
a government official makes a person reasonably believe that he or she is not at
liberty to ignore the government’s presence and go about his business in view of all
the circumstances surrounding the incident.12 Additionally, a refusal to cooperate,
without more, does not furnish the minimal level of objective justification needed for
a detention or seizure.13 A seizure of a person, therefore, can include full arrests,
investigatory detentions, checkpoint stops for citizenship inquiries, and detentions
of a person against his will. The Supreme Court has identified a number of factors
that might suggest that a seizure has occurred, including: (1) the intimidating
presence or movement of officers; (2) the display of weapons; (3) the application of
physical force; and (4) the authoritative tone of voice used by officers.14
8 Camara v. Municipal Court, 387 U.S. 523, 539-540 (1967).
9 See Oliver v. United States, 466 U.S. 170, 177-78 (1984); see also Walter v. United States,
447 U.S. 649, 656 (1980) (noting that a wrongful search or seizure conducted by a private
party does not violate the Fourth Amendment. . . .).
10 INS v. Lopez-Mendoza, 468 U.S. 1032 (1984); see also Mapp v. Ohio, 367 U.S. 643, 648
(1961) (exclusionary rule in general).
11 Sodal v. Cook County, 506 U.S. 56, 61 (1992) quoting United States v. Jacobsen, 466 U.S.
109, 113 (1984).
12 Florida v. Bostick, 501 U.S. 429, 437 (1991) citing Michigan v. Chesternut, 486 U.S. 567,
573 (1988).
13 Immigration and Naturalization Service v. Delgado, 466 U.S. 210, 216 (1984).
14 See United States v. Drayton, 536 U.S. 194 (2002); see also United States v. Mendenhall,
446 U.S. 544, 554 (1980).

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Search. Historically, a “search” entailed some type of government invasion
into a “constitutionally protected area.”15 Early courts looked to the enumerated areas
described in the Fourth Amendment to determine what was a “constitutionally
protected area” (i.e., “persons, houses, papers, and effects”).16 These courts soon
began to emphasize property principles in their Fourth Amendment analysis.17 Not
until the landmark decision of Katz v. United States in 1967 did the Supreme Court
abandon its structural “property” approach for a fluid constitutional framework that
was to “protect people, not places.”18
Katz involved eavesdropping by means of an electronic surveillance device
attached to the exterior of a public telephone booth — a location not within the
enumerated constitutional protections (i.e., persons, houses, papers, and effects). The
lower courts concluded that no search took place since the electronic surveillance
device did not penetrate the wall of the telephone booth. The Supreme Court,
however, stepped away from its historical property principles and proclaimed that
the reach of the Fourth Amendment could not turn upon the presence or absence of
a physical intrusion into a given enclosure. Although the majority in Katz
demonstrated a new understanding of the term “search,” it was Justice Harlan’s
concurring opinion that articulated the basic standard courts emphasize today.
According to Justice Harlan’s concurrence, a “search” does not occur for
purposes of the Fourth Amendment unless (1) the individual manifested a subjective
expectation of privacy in the searched object and (2) society is willing to recognize
that expectation as reasonable or legitimate.19 In essence, an impermissible “search”
occurs when there is an infringement of an expectation of privacy that society is
prepared to consider reasonable. Legitimate expectations of privacy must have a
source outside of the Fourth Amendment, either by reference to concepts of real or
personal property law or to understandings that are recognized and permitted by
society.20 Among the factors to be considered in determining whether a defendant
had a legitimate expectation of privacy in addition to the proprietary or possessory
interest in the place to be searched, are (1) whether the defendant has the right to
exclude others from the place in question; (2) whether he has exhibited a subjective
15 Silverman v. United States, 365 U.S. 505 (1961); Berger v. New York, 388 U.S. 41 (1967).
16 See, e.g., Beck v. Ohio, 379 U.S. 89 (1964) (person’s clothing); Clinton v. Virginia, 377
U.S. 158 (1964) (apartment); Preston v. United States, 376 U.S. 364 (1964) (automobile
interpreted as an effect).
17 See Goldman v. United States, 316 U.S. 129, 134-135 (1942) (applying a trespass equals
search analysis); Olmstead v. United States, 277 U.S. 438 (1928) (same).
18 389 U.S. 347, 351 (1967). See also Warden v. Hayden, 387 U.S. 294, 304 (1967) (“We
have recognized that the principal object of the Fourth Amendment is the protection of
privacy rather than property, and have increasingly disregarded fictional and procedural
barriers rested on property concepts.”).
19 Katz, 389 U.S. at 357 (Harlan, J., concurring).
20 Minnesota v. Carter, 525 U.S. 83, 88 (1998).

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expectation that the area would remain free from governmental intrusion; and (3)
whether he was legitimately on the premises.21
In an effort to detect and search increasingly sophisticated smugglers, officials
today have begun to rely more heavily on advanced technologies that seemingly
intrude into our daily lives, often without our knowledge. The use of such devices
may blur the line between expectations of privacy that are legitimate and those that
are not. The Supreme Court addressed this issue in Kyllo v. United States when it
considered the constitutional limits upon the government’s use of sensory-enhancing
technology.22 The Kyllo Court determined that the use of a thermal-imaging device
to detect heat waves emitted from a home was a “search” partly because all details
in the home are intimate (i.e., a person has a subjective and reasonable expectation
of privacy in the interior of his home).23 As a result, the Court held that where the
government uses a device that is not in general public use, to explore details of the
home or a “constitutionally protected area” that would previously have been
unknowable without physical intrusion, the surveillance is a “search” and is
presumptively unreasonable without a warrant.24 The Court felt that the Fourth
Amendment was to be construed in the light of what was deemed an unreasonable
search and seizure when it was adopted,25 but nonetheless, opined that it would “be
foolish to contend that the degree of privacy secured to citizens by the Fourth
Amendment has been entirely unaffected by the advance of technology.”26
Border Searches
Warrantless searches are per se unreasonable under the Fourth Amendment,
unless a court determines that the search is subject to an established exception. The
border search, although a warrantless search in general, is among the more well-
recognized and long established exceptions to the Fourth Amendment’s probable
cause and warrant requirements. Authorized by the First Congress,27 the border
search exception has a history as old as the Fourth Amendment and obtains its broad
power from Congress’s authority to regulate commerce with foreign nations and to
enforce immigration laws.28 The Fourth Amendment does not require warrants or
probable cause for routine stops and searches at the border because it is within the
21 United States v. Elmore, 304 F.3d 557, 562 (6th Cir. 2002).
22 533 U.S. 27, 34 (2001).
23 Id. at 37.
24 Id. at 40.
25 Id. citing Carroll v. United States, 267 U.S. 132, 149 (1925). Accordingly, the Fourth
Amendment draws a firm line at the entrance of the home against unreasonable searches and
requires clear specification of those methods of surveillance that require a warrant.
26 Kyllo, 533 U.S. at 33-34.
27 Act of July 31, 1789, ch.5 §§23-24, 1 Stat. 29, 43 (current version at 19 U.S.C. §§482,
1582).
28 United States v. Ramsey, 431 U.S. 606, 619 (1977) (citing U.S. Const., Art. I, §8, cl. 3).

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power of the federal government to protect itself by inspecting persons and property
entering and leaving the country.29
Although the border search is an exception to the Fourth Amendment’s warrant
and probable cause requirements, it is not exempt from the Fourth Amendment’s
“reasonableness” standard because a “search” has still occurred (i.e., the
government’s search is still subject to the balancing scale).30 Courts have determined
that border searches usually fall into two categories — routine and nonroutine.
Generally, the distinction between “routine” and “nonroutine” turns on the level of
intrusiveness. Routine border searches are reasonable simply by virtue of the fact
that they occur at the border and consist of only a limited intrusion, while nonroutine
searches generally require reasonable suspicion and vary in technique and
intrusiveness.31 Border searches may occur when entry is made by land from the
neighboring countries of Mexico or Canada, at the place where a ship docks in the
U.S. after having been to a foreign port, and at any airport in the country where
international flights first land. In general, authorities at the border may search a
person entering or leaving the country, an individual’s automobile, baggage, or
goods, and inbound and outbound international materials.32
Functional Equivalent. Border searches may also be conducted within the
interior of the United States. The border search exception extends to those searches
conducted at the “functional equivalent” of the border. The “functional equivalent”
of a border is generally the first practical detention point after a border crossing or
the final port of entry.33 It is justified because in essence, it is no different than a
search conducted at the border and occurs only because of the impossibility of
requiring the subject searched to stop at the physical border. A search occurs at the
border’s functional equivalent when: (1) a reasonable certainty exists that the person
or thing crossed the border; (2) a reasonable certainty exists that there was no change
in the object of the search since it crossed the border; and (3) the search was
29 See Ramsey, 431 U.S. at 616. It should be noted that many of nation’s border security
agencies or functions have been transferred to the newly created Department of Homeland
Security. See P.L. 107-296. For purposes of consistency, this report refers to agency names
as maintained in the case law.
30 Marsh v. United States, 344 F.2d 317, 324 (5th Cir. 1965).
31 For a more thorough explanation on the distinctions between routine and nonroutine
searches see page 9, Types of Searches and Seizures at the Border.
32 See Ramsey, 431 U.S. 606 (inbound international mail); United States v. Ezeiruaku, 936
F.2d 136 (3d. Cir. 1991) (routine searches of outbound materials). The 5th Circuit has found
the search of outbound materials permissible when: (1) the outbound search is at the border
or its functional equivalent; (2) Customs agents have reasonable suspicion that a particular
traveler will imminently engage in the felonious transportation of specific contraband in
foreign commerce; and (3) the search is relatively unintrusive and only of the area where the
contraband is allegedly secreted. United States v. Roberts, 274 F.3d 1007, 1014 (5th Cir.
2001).
33 Thirty-First Annual Review of Criminal Procedure; Border Searches, 90 Geo. L.J. 1087,
1190 (2002).

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conducted as soon as practicable after the border crossing.34 Places such as
international airports within the country and ports within the country’s territorial
waters or stations at the intersection of two or more roads extending from the border
exemplify such functional equivalents.35 In general, courts have given the “border”
a geographically flexible reading because of the significant difficulties in detecting
the increasingly mobile smuggler.
Extended Border Search. The border search exception may be extended
to allow warrantless searches beyond the border or its functional equivalent. Under
the “extended border search” doctrine, government officials may conduct a
warrantless search beyond the border or its functional equivalent if (1) the
government officials have reasonable certainty or a “high degree of probability” that
a border was crossed; (2) they also have reasonable certainty that no change in the
object of the search has occurred between the time of the border crossing and the
search; and (3) they have “reasonable suspicion” that criminal activity was
occurring.36 This three-part test ensures that a suspect still has a significant nexus
with a border crossing so that border officials can reasonably base their search on
statutory and constitutional authority and to ensure that the search is reasonable.37
Although a search at the border’s functional equivalent and an extended border
search require similar elements, the extended border search entails a greater intrusion
on a legitimate expectation of privacy, and thus, requires a showing of “reasonable
suspicion” of criminal activity. Another difference between the functional equivalent
of a border search and an extended border search is that the latter takes place after the
first point in time when the entity might have been stopped within the country.38 For
example, in United States v. Teng Yang, the 7th Circuit upheld an extended border
search that occurred at an international airport but at a time after the Defendant’s
initial inspection process and at a location away from the designated U.S. border
inspection sites.39 The court determined that “[i]t is the enforcement of the customs
laws combined with the mandate of protecting the border of the United States that
permits the extension of the search rights of border authorities to allow non-routine
searches in areas near our nations’s borders.”40 Due to the dynamics of cross-border
travel, the extended border search doctrine has gained wide acceptance among the
34 See United States v. Hill, 939 F.2d 934, 936 (11th Cir. 1991).
35 Almeida-Sanchez v. United States, 413 U.S. 266, 272-73 (1973).
36 “Reasonable certainty” in this context has been defined as a standard which requires more
than probable cause, but less than proof beyond a reasonable doubt. United States v.
Cardenas
, 9 F.3d 1139, 1148 (5th Cir. 1993); see, e.g.,United States v. Delgado, 810 F.2d
480, 482 (5th Cir. 1987). In Delgado, smugglers used a foot-bridge to transfer narcotics to
delivery trucks on a farm near El Paso, Texas. The court upheld an extended border search
conducted on a farm road near and leading from the border but otherwise away from the
official border checkpoint.
37 United States v. Teng Yang, 286 F.3d. 940, 946 (7th Cir. 2002).
38 United States v. Niver, 689 F.2d 520, 526 (5th Cir. 1982).
39 286 F.3d. 940 (7th Cir. 2002).
40 Id. at 947.

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courts because it strikes a sensible balance between the legitimate privacy interests
of the individual and society’s vital interest in the enforcement of U.S. laws.41
At Sea. Searches of persons and conveyances crossing our international
borders are reasonable simply because of the fact that they occur at the border.
Similar to land-based situations, the border search exception to the Fourth
Amendment’s probable cause and warrant requirements also applies to vessels
entering the territorial seas of the United States. Government officials may board any
vessel in U.S. territorial waters or the high seas without a warrant or reasonable
suspicion of criminal activity to conduct routine document and safety inspections if
the vessel is subject to the jurisdiction or the operation of any U.S. law.42 The United
States has plenary power over its territorial seas, which generally extend three miles
from the coast,43 but may also enforce its laws up to twelve miles from the coast.44
Thus, a ship that docks at a port within the United States’ territorial waters (i.e., the
functional equivalent of the border) after arriving from a foreign country or a ship
that crosses our nation’s coastal boundaries may be subjected to a routine
suspicionless and warrantless search.
Courts have limited such warrantless and suspicionless searches to examining
the ship’s documents, visiting the ship’s public areas, and entering a ship’s storage
compartments.45 Because there is a reasonable expectation of privacy in the
nonpublic areas of a ship, reasonable suspicion is required to conduct a limited search
that extends beyond document and safety inspections. Moreover, probable cause or
consent is required for full stem-to-stern searches or seizures.46 For example, in
United States v. Cardona-Sandoval, the court concluded that the captain and crew of
a small pleasure boat had a reasonable expectation of privacy in all areas of the
41 See, e.g., Teng Yang, 286 F.3d. 940; United States v. Espinoza-Seanez, 862 F.2d 526 (5th
Cir. 1989); United States v. Caicedo-Guarnizo, 723 F.2d 1420 (9th Cir. 1984); United States
v. Garcia
, 672 F.2d 1349 (11th Cir. 1982); United States v. Bilir, 592 F.2d 735 (4th Cir.
1979).
42 See United States v. Villamonte-Marquez, 462 U.S. 579, 592-593 (1983) (reasonable
under
Fourth Amendment for Customs, acting pursuant to statutory authority, to board vessel in
domestic waters and inspect documents); see also United States v. Cilley, 785 F.2d 651, 654
(9th Cir. 1985) (reasonable under Fourth Amendment for Coast Guard to stop and board U.S.
vessel to conduct safety inspection pursuant to safety inspection laws).
43 United States v. Warren, 578 F.2d 1058 (5th Cir. 1978).
44 United States v. Williams, 617 F.2d 1063, 1073 (5th Cir. 1980); 19 U.S.C. 1401.
45 See Villamonte-Marquez, 462 U.S. at 592 (intrusion limited to document inspection and
public areas); United States v. Merritt, 736 F.2d 223, 230 (5th Cir. 1984) (Customs may
check main beam number in hold of vessel). Public areas of the vessel include the engine
room, ice holds, and cargo holds. See, e.g., United States v. Pinto-Mejia, 720 F.2d 248, 255
(2d Cir 1983) (cargo holds); United States v. Arra, 630 F.2d 836, 842 (1st Cir. 1980) (engine
room); United States v. De Weese, 632 F.2d 1267, 1271 (5th Cir. 1980) (ice holds).
46 See, e.g., United States v. Roy, 869 F.2d 1427, 1430-33 (11th Cir. 1989) (limited search of
vessel based on reasonable suspicion valid, but stem-to-stern search required probable
cause).

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vessel, much like a host and overnight guests in a small apartment.47 The Cardona-
Sandoval
court nevertheless validated a limited search of the vessel pursuant to the
government’s reasonable suspicion of criminal activity but invalidated a subsequent
seizure and destructive search due to the lack of probable cause.48 In general, routine
inspections of vessels entering into the U.S. may be conducted without a warrant,
probable cause, or reasonable suspicion of illegal activity, because a sovereign has
the right to protect its borders.
Types of Searches and Seizures at the Border
Routine Searches. In order to regulate the collection of duties and to prevent
the introduction of illegal aliens and contraband into this country, Congress has
granted the Executive plenary power to conduct routine searches of persons, luggage,
personal belongings, and vehicles without reasonable suspicion, probable cause, or
a warrant.49 In fact, routine searches made at the border require no suspicion and are
“reasonable” simply by the fact that they occur at the border.50 A routine border
search is a search that does not pose a serious invasion of privacy or offend the
average traveler.51 For example, a routine border search may consist of limited
searches for contraband or weapons through a pat-down,52 the removal of outer
garments such as jackets, hats, or shoes, the emptying of pockets, wallets, or purses,53
the use of a drug-sniffing dog,54 the inspection of cars,55 and some x-ray searches of
47 6 F.3d 15, 22 (1st Cir. 1993). The court also concluded that the recent construction,
unusual thickness of the walls, and general unkempt state of the vessel created a reasonable
suspicion of criminal activity.
48 Id.
49 See, e.g.,8 U.S.C. §1357(c) (authorizing immigration officials to search without a warrant
persons entering the country for evidence which may lead to the individual’s exclusion); 19
U.S.C. §1496 (authorizing customs officials to search the baggage of person entering the
country); 19 U.S.C. §1582 (authorizing customs officials to detain and search all persons
coming into the Untied States from foreign countries); see also United States v. Montoya
de Hernandez
, 473 U.S. 531, 538 (1985).
50 United States v. Odland, 502 F.2d 148 (7th Cir. 1974) citing Carroll v. United States, 267
U.S. 132, 153 (1925). Some courts have indicated a need for “mere suspicion” to conduct
a routine border search, which usually requires at least some knowledge identifying an
individual as a suspect. See e.g., Rodriguez-Gonzalez v. United States, 378 F.2d 256 (9th
Cir. 1967) (also using the term “unsupported suspicion”). This standard, however, is an
inaccurate articulation of the general rule that no suspicion is required. See Odland, 502
F.2d at 151 (“Any person or thing coming into the United States is subject to search by that
fact alone, whether or not there be any suspicion of illegality directed to the particular
person or thing to be searched.”); Bradley v. United States, 299 F.3d 197, n.7 (3d Cir. 2002)
(stating “mere suspicion” standard effectively overruled by Montoya de Hernandez).
51 United States v. Johnson, 991 F.2d 1287, 1291 (7th Cir. 1993).
52 See, e.g., United States v. Beras, 183 F.3d 22, 24 (1st Cir. 1999) (holding that a patdown
of an international traveler’s legs was not intrusive enough to qualify as nonroutine).
53 United States v. Sandler, 644 F.2d 1163, 1169 (5th Cir. 1981).
54 United States v. Kelly, 302 F.3d 291, 294-95 (5th Cir. 2002) (sniff by a dog of a person at
(continued...)

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inanimate objects.56 The consistent approval of routine border searches by courts
reflects a longstanding concern for the protection of the integrity of the border.
It has long been established that an individual’s reasonable expectation of
privacy is lower at the border than in the interior of the country. In essence, because
a person crossing the border is on notice that a search may be likely, his privacy is
“less invaded by those searches.”57 A person crossing the border apparently has an
opportunity to decrease the amount of intrusion by limiting the nature and character
of the items which he brings with him.58 Routine border searches are also arguably
less intrusive because they are administered to a class of people (international
travelers) rather than to individuals.59 The degree of intrusiveness or invasiveness
associated with the particular technique is particularly helpful in determining whether
a search is routine. The First Circuit, for example, compiled a nonexhaustive list of
six factors to be considered: (1) whether the search required the suspect to disrobe
or expose any intimate body parts; (2) whether physical contact was made with the
suspect during the search; (3) whether force was used; (4) whether the type of search
exposed the suspect to pain or danger; (5) the overall manner in which the search was
conducted; and (6) whether the suspects’s reasonable expectations of privacy, if any,
were abrogated by the search.60
Nonroutine Searches. Once a personal search by a government official goes
beyond a limited intrusion, a court may determine that a nonroutine search has
occurred. In general, nonroutine border searches are conducted in order to detect and
search individuals who have resorted to alimentary canal smuggling. Nonroutine
border searches may include searches of inanimate objects, prolonged detentions,
strip searches, body cavity searches, and some x-ray examinations.61 At the very
54 (...continued)
the border upheld as a routine border search); cf. United States v. Garcia-Garcia, 319 F.3d
726, 730 (5th Cir. 2003) (dog sniff of a person on a bus at an immigration checkpoint upheld
and seen as analogous to a pat down).
55 Almeida-Sanchez v. United States, 413 U.S. 266, 272 (1973); United States v. Uribe-
Galindo
, 990 F.2d 522, 525-526 (10th Cir. 1993); United States v. Mendoza-Gonzalez, 318
F.3d 663, 666 (5th Cir. 2003).
56 United States v. Okafor, 285 F.3d 842 (9th Cir. 2002) (finding an x-ray examination and
subsequent probe of luggage a routine search because it requires no force, poses no risk to
the bag’s owner or to the public, causes no psychological fear, and does not harm the
baggage).
57 Gary N. Jacobs, Note, Border Searches and the Fourth Amendment, 77 Yale L.J. 1007,
1012 (1968).
58 It should be noted that the “reasonable person” test presupposes an innocent person.
Florida v. Bostick, 501 U.S. 429, 437 (1991).
59 77 Yale L.J. 1007, 1012 (1968).
60 United States v. Braks, 842 F.2d 509, 511-12 (1st Cir. 1988). The Braks court concluded
that only strip searches and body cavity searches are consistently nonroutine.
61 See, e.g., United States v. Molina-Tarazon, 279 F.3d 709 (9th Cir. 2002) (disassembly of
(continued...)

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least, it appears courts require a government official have a “reasonable suspicion”
of illegal activity to conduct a nonroutine border search on an individual entering the
country.62 The reasonable suspicion standard generally requires an officer at the
border to have “a particularized and objective basis for suspecting the particular
person” of wrongdoing.63 For example, in United States v. Forbicetta, the court
found reasonable suspicion to exist where Customs officials acted on the following
objective facts: (1) the suspect arrived from Bogota, Colombia, (2) was traveling
alone, (3) had only one suitcase and no items requiring Customs inspection, (4) was
young, clean-looking, and attractive, and (5) was wearing a loose-fitting dress.64
Some courts, however, have required a higher degree of suspicion to justify the more
intrusive of the procedures.65
The Supreme Court has not articulated the level of suspicion required for the
various nonroutine border searches or the factors that render a border search routine
or nonroutine;66 however, in United States v. Montoya de Hernandez the Supreme
Court concluded that a third suspicion standard (i.e., clear indication) in addition to
“reasonable suspicion” and “probable cause” was not consistent with the Fourth
Amendment’s emphasis upon reasonableness in the prolonged detention setting.67
The Court determined that the “clear indication” standard (a suggestion that is free
from doubt) was to be used to indicate the necessity for particularized suspicion,
“rather than as enunciating a third Fourth Amendment threshold between ‘reasonable
suspicion’ and ‘probable cause.’”68 Although the Court has not articulated a level of
suspicion for all nonroutine searches, courts have viewed the Montoya de Hernandez
61 (...continued)
a car); United States v. Reyes, 821 F.2d 168, 170-71 (2d Cir. 1987) (strip search); United
States v. Oyekan
, 786 F.2d 832, 837 (8th Cir. 1986) (strip search); United States v. Adekunle,
2 F.3d 559, 562 (5th Cir. 1993) (continued detention and x-ray examination of alimentary
canal); United States v. Rivas, 157 F.3d 364, 367 (5th Cir. 1998) (drilling of hole into body
of automobile).
62 United States v. Montoya de Hernandez, 473 U.S. 531, 541 (1985); United States v.
Garcia-Garcia
, 319 F.3d 726, 730 (5th Cir. 2003) (an alert by a drug sniffing dog provided
reasonable suspicion to detain a bus long enough to investigate the reason for the dog’s
response).
63 See Montoya de Hernandez, 473 U.S. at 541 citing Terry v. Ohio, 392 U.S. 1, 21 (1968)
(“And in justifying the particular intrusion the police officer must be able to point to specific
and articulable facts which, taken together with rational inferences from those facts,
reasonably warrant that intrusion.”).
64 484 F.2d 645 (5th Cir. 1973). These factors taken together matched the “smuggling
profile” for narcotic carriers in that area, and thus, the court concluded there was a sufficient
basis to conduct the search. But see Reid v. Georgia, 448 U.S. 438, 441(1980) (rejecting the
argument that arrival from a source location could, by itself, provide reasonable suspicion).
65 See, e.g., United States v. Ramos-Saenz, 36 F.3d 59, 61 (9th Cir. 1994) (requiring the
higher “clear indication” standard for a body cavity search); United States v. Ek, 676 F.2d
379, 382 (9th Cir. 1982) (requiring a “clear indication” for x-ray search).
66 See Montoya de Hernandez, 473 U.S. at 541 n.4.
67 Id. at 541.
68 Id. at 540.

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reasoning as a warning against the development of multiple gradations of suspicion
for nonroutine border searches in general.69
Searches of Inanimate Objects. A physical or x-ray search of an
inanimate object is considered to be a routine search because it generally does not
pose the same degree of intrusiveness as searches of the human body. However, a
routine search of an inanimate object such as a person’s luggage or car may become
so intrusive that it rises to the level of intrusiveness associated with a strip or body
cavity search. Accordingly, where a court determines an intrusive search of an
inanimate object has occurred, it will require “reasonable suspicion.”
For example, the 9th Circuit in United States v. Molina-Tarazon, held that the
dismantling and removal of a truck’s fuel tank by Customs’ agents was a nonroutine
search.70 The dismantling of the truck was nonroutine because of (1) the force used
in conducting the search, (2) the risk of harm the search posed, and (3) the potential
fear instilled in the truck’s owner if left no choice but to drive a reassembled truck.71
The court, however, ultimately upheld the nonroutine search because it was based on
reasonable suspicion. In United States v. Okafor, the 9th Circuit determined that an
x-ray search of luggage simply did not present the same level of intrusiveness
associated with the search in Molina-Tarazon. The court qualified its holding,
however, stating that an x-ray search of luggage “may be done at the border with no
required showing of particularized suspicion, at least so long as the means of
examination are not personally intrusive, do not significantly harm the objects
scrutinized, and do not unduly delay transit.”72 Ultimately, the question of whether
a search of an inanimate object is routine or nonroutine will turn on the level of
intrusiveness.
Prolonged Detentions. Prolonged detentions are seizures conducted in
order to either verify or dispel an agent’s suspicion that a traveler will introduce a
harmful agent into the country through alimentary canal smuggling. In United States
v. Montoya de Hernandez,
the Supreme Court was confronted with a passenger on
a flight from Bogota, Columbia, suspected of alimentary canal smuggling who
refused to consent to an x-ray examination. In an attempt to verify or dispel their
69 United States v. Charleus, 871 F.2d 265, 268 n.2 (2d Cir. 1989); United States v. Oyekan,
786 F.2d 832, 837-39 (8th Cir. 1986); Bradley v. United States, 299 F.3d 197, 202-04 (3d
Cir. 2002). United States v. Aguebor, 1999 U.S. App. Lexis 25, at *9 (4th Cir. Jan. 4, 1999)
(this unpublished opinion is cited merely as an example and is not intended to have
precedential value). According to Professor LaFave, however, extending Montoya de
Hernandez
to other nonroutine searches would require a broad reading of the case, which
doesn’t consider the fact that body cavity searches are more intrusive. See 4 Wayne R.
LaFave, Search and Seizure, A Treatise on the Fourth Amendment §10.5(e), 556 (3d ed.
1996 & Supp. 2003).
70 United States v. Molina-Tarazon, 279 F.3d 709 (9th Cir. 2002).
71 Id. at 713-17.
72 United States v. Okafor, 285 F.3d 842, 846 (9th Cir. 2002).

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suspicions, Customs detained Ms. de Hernandez for over 16 hours and told her she
could not leave until she had excreted into a wastebasket.73
The Court determined “that the detention of a traveler at the border, beyond the
scope of a routine Customs search and inspection, is justified at its inception if
Customs agents, considering all the facts surrounding the traveler and her trip,
reasonably suspect that the traveler is smuggling contraband in her alimentary
canal.”74 The Court concluded that it was reasonable to detain Ms. de Hernandez for
the period of time necessary to either verify or dispel the suspicion of the agents in
these circumstances. Courts have reasoned that “an otherwise permissible border
detention does not run afoul of the Fourth Amendment simply because a detainee’s
intestinal fortitude leads to an unexpectedly long period of detention.”75 Notably
however, the Fifth Circuit in United States v. Adekunle concluded that the
government must, within a reasonable time (generally within 48 hours), seek a
judicial determination that reasonable suspicion exists to detain a suspect for an
extended period of time.76
Strip Searches. A strip search consists of removing one’s clothing either all
or in part to a state which would be offensive to the average person. Accordingly,
reviewing courts generally require the presence of reasonable suspicion that a person
is concealing something illegal on the place to be searched in order for such a search
to be justified. Because strip searches generally involve an embarrassing imposition
upon a traveler, it appears to be unreasonable to conduct such searches without
reasonable suspicion.77 Often, routine searches give rise to the reasonable suspicion
required to conduct strip searches. For instance, in United States v. Flores, upon
discovering 600 small undeclared emerald stones in the defendant’s pockets during
a routine search, Customs agents conducted a strip search and discovered an envelope
73 According to Professor LaFave, Montoya de Hernandez does not stand for a “detention
until defecation” proposition. The court narrowly decided that the particular detention “was
not unreasonably long” under “these circumstances.” In fact, the agents expected Ms. de
Hernandez to produce a bowel movement without extended delay because she had just
disembarked from a 10-hour flight. 4 Wayne R. LaFave, Search and Seizure, A Treatise on
the Fourth Amendment §10.5(b), 546 (3d ed. 1996 & Supp. 2003).
74 Montoya de Hernandez, 473 U.S. at 541. See also United States v. Esieke, 940 F.2d 29
(2d Cir. 1991) (court upheld a detention of one and half days before first bowel movement
and another two and half days until all balloons were expelled); United States v. Yakubu,
936 F.2d 936 (7th Cir. 1991) (16 hour detention upheld after refusal to be x-rayed).
75 Esieke, 940 F.2d at 35.
76 2 F.3d 559, 562 (5th Cir. 1993). The court opined that a formal determination is not
necessary, rather, an informal presentation of the evidence supporting the government’s
suspicion before a neutral and detached judicial officer satisfies this requirement.
Furthermore, the court concluded that the failure to obtain such a judicial determination
within 48 hours shifts the burden to the government to demonstrate a bona fide emergency
justifying the extended detainment.
77 United States v. Chase, 503 F.2d 571 (9th Cir. 1974).

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of narcotics.78 The court held that the prior discovery of the emeralds contrary to law
was clearly sufficient to meet the higher level of suspicion necessary to conduct the
strip search.79
Body Cavity Searches. Because government officials are well aware of
narcotic smuggling that is concealed in the body cavities of travelers, searches into
such cavities have become more common place. Body cavity searches may include
inspections of the vagina, rectum, or the use of emetics.80 Because of the extreme
medical risks involved in internal drug smuggling, courts have determined that body
cavity searches do not require the advance procurement of a search warrant from a
magistrate.81 In general, a border official must “reasonably suspect” that an
individual is attempting to smuggle contraband inside his body for a court to justify
a body cavity search.82 Some courts historically required a “clear indication” (a
suggestion that is free from doubt) of alimentary canal smuggling due to the
significant intrusion beyond the body’s surface.83 However, ever since the Supreme
Court articulated a more general, but firm rejection of the “subtle verbal gradations”
being developed by courts of appeals to enunciate the Fourth Amendment standard
of reasonableness, courts have apparently been unwilling to adopt the “clear
indication” standard in the context of body cavity searches.84 Additionally, the
manner in which the body cavity search is conducted must also be reasonable in light
of the circumstances. Generally, conduct that “shocks the conscience” is inherently
78 477 F.2d 608 (1st Cir. 1973).
79 Id.
80 E.g., United States v. Ogberaha, 771 F.2d 655, 657 (2d Cir. 1985) (vagina); United States
v. Pino
, 729 F.2d 1357, 1358 (11th Cir. 1984) (rectum); Untied States v. Briones, 423 F.2d
742, 743 (5th Cir. 1970) (emetics).
81 See, e.g., United States v. Sosa, 469 F.2d 271 (9th Cir. 1972) (no warrant for rectal probe);
United States v. Mason, 480 F.2d 563 (9th Cir. 1973) (no warrant for vaginal probe); United
States v. Briones
, 423 F.2d 742 (5th Cir. 1970) (no warrant for administration of an emetic).
But see United States v. Holtz, 479 F.2d 89 (9th Cir. 1973) (Ely, J., dissenting); Blefare v.
United
, 362 F.2d 870 (9th Cir. 1966) (Ely, J., dissenting).
82 See, e.g.,United States v. Ogberaha, 771 F.2d 658 (2d Cir. 1985); Swain v. Spinney, 117
F.3d 1, 7 (1st Cir. 1997) (only required reasonable suspicion for visual body cavity search);
United States v. Gonzalez-Ricon, 36 F.3d 859, 864 (9th Cir. 1984) (noting in dictum that a
body cavity search must be supported by reasonable suspicion).
83 See, e.g., United States v. Ramos-Saenz, 36 F.3d 59, 61 (9th Cir. 1994) (affirming clear
indication standard).
84 See, e.g.,United Stats v. Ogberaha, 771 F.2d 658 (2d Cir. 1985); Swain v. Spinney, 117
F.3d 1, 7 (1st Cir. 1997) (only required reasonable suspicion for visual body cavity search);
United States v. Bravo, 295 F.3d 1002, (9th Cir. 2002) (noting in dictum that a body cavity
search must be supported by reasonable suspicion).

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unreasonable.85 Such conduct has included that use of a stomach pump86 and could
potentially include medical procedures performed by nonmedical personnel.87
X-Ray Searches. X-ray searches have also been used at the border, instead
of, or in conjunction with, body cavity searches. X-ray searches raise Fourth
Amendment concerns because they locate items where there is normally an
expectation of privacy. Their level of intrusion has been questioned by courts
because they do not constitute an actual physical invasion but can pose harmful
medical effects.88 A question arises as to whether an involuntary x-ray search is more
akin to a strip search, and thus only requires a “reasonable suspicion,” for its
application, or whether the intrusion is so great that it could potentially require a
greater level of suspicion.
In examining this issue, the 11th Circuit in United States v. Vega-Barvo
determined that an x-ray search is no more intrusive than a strip search.89 The Vega-
Barvo
court examined (1) the physical contact between the searcher and the person
searched; (2) the exposure of intimate body parts; and (3) the use of force.90 These
factors helped the court examine the level of intrusiveness endured by the defendant
and to ultimately conclude that the government agents, acting under a reasonable
suspicion of illegal activity, properly detained and x-rayed the smuggler. The court
reasoned that x-rays do not require physical contact or usually expose intimate body
parts. Further, the court noted that hospitals generally will not perform an x-ray
without a person’s consent. The court also determined that “an x-ray is one of the
more dignified ways of searching the intestinal cavity.”91 In general, courts have
likened x-ray searches to strip searches, and thus, “reasonable suspicion” is the level
of suspicion necessary to conduct an x-ray examination of a suspected alimentary
canal smuggler.92
85 Rochin v. California, 342 U.S. 165 (1952).
86 Id.
87 Rectal searches have been upheld when conducted by medical personnel using accepted
and customary medical techniques in medical surroundings. See, e.g., Rivas v. United
States
, 368 F.2d 703 (9th Cir. 1966) (upholding rectal search by a doctor at doctor’s office).
There is little case law on vaginal searches, however rectal search cases are arguably
analogous.
88 United States v. Vega-Barvo, 729 F.2d 1341, 1345 (11th Cir. 1984) (asking whether an x-
ray is more intrusive than a cavity search because it will reveal more than the cavity search,
or less intrusive because it does not infringe upon human dignity to the same extent as a
search of private parts).
89 Id. at 1341.
90 Vega-Barvo, 729 F.2d at 1346.
91 Id. at 1348.
92 Although some courts required a “clear indication” for x-ray searches, courts now
generally analogize x-rays with strip searches, and thus, only require reasonable suspicion.
Compare United States v. Ek, 676 F.2d 379, 382 (9th Cir. 1982) (determining that while an
x-ray search may not be as humiliating as a strip search, “it is more intrusive since the search
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Conclusion
In light of the aforementioned cases, it is evident that the courts have
consistently recognized the longstanding right of the United States to protect itself
by inspecting persons and property entering the country. As an exception to the
Fourth Amendment’s probable cause and warrant requirements, the routine border
search will continue to play a significant role in border management. The new
threats of the 21st century, however, may necessitate the acquisition and use of
advanced detection devices or procedures which will require the courts to again look
at the degree of indignity suffered by an individual and the level of intrusiveness of
the search to determine its placement among the routine and nonroutine searches.
Additionally, as threats at our borders become more sophisticated, nonroutine
searches supported by “reasonable suspicion” will become an increasingly important
tool to detect travelers attempting to enter the U.S. in violation of its laws. From the
proceeding discussion, it appears the border search exception to the Fourth
Amendment through its routine and nonroutine procedures maintains a flexibility that
affords the full measure of Fourth Amendment protections while facilitating the
nation’s endeavor to protect the mainland.
92 (...continued)
is potentially harmful to the health of the suspect”) with United States v. Oyekan, 786 F.2d
832, 837 (8th Cir. 1986) (requiring reasonable suspicion for x-ray search); United States v.
Pino
, 729 F.2d 1357, 1359 (11th Cir. 1984) (x-ray search equal to strip search).