UNITED STATES v. FLORES-MONTANO

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149 OCTOBER TERM, 2003
Syllabus
UNITED STATES v. FLORES-MONTANO
certiorari to the united states court of appeals for
the ninth circuit
No. 02–1794. Argued February 25, 2004—Decided March 30, 2004
At the international border in southern California, customs officials seized
37 kilograms of marijuana from respondent’s gas tank by removing and
disassembling the tank. After respondent was indicted on federal drug
charges, he moved to suppress the drugs recovered from the gas tank,
relying on a Ninth Circuit panel decision holding that a gas tank’s re-
moval requires reasonable suspicion under the Fourth Amendment.
The District Court granted the motion, and the Ninth Circuit sum-
marily affirmed.
Held: The search did not require reasonable suspicion. In the decision
relied on below, the Ninth Circuit panel seized on language from United
States v. Montoya de Hernandez, 473 U. S. 531, 538, that used “routine”
as a descriptive term in discussing border searches. The panel took
“routine,” fashioned a new balancing test, and extended it to vehicle
searches. But the reasons that might support a suspicion requirement
in the case of highly intrusive searches of persons simply do not carry
over to vehicles. Complex balancing tests to determine what is a “rou-
tine” vehicle search, as opposed to a more “intrusive” search of a person,
have no place in border searches of vehicles. The Government’s inter-
est in preventing the entry of unwanted persons and effects is at its
zenith at the international border. United States v. Ramsey, 431 U. S.
606, 616. Congress has always granted the Executive plenary authority
to conduct routine searches and seizures at the border, without probable
cause or a warrant, in order to regulate the collection of duties and
to prevent the introduction of contraband into this country. Montoya
de Hernandez, 473 U. S., at 537. Respondent’s assertion that he has a
privacy interest in his fuel tank, and that the suspicionless disassembly
of his tank is an invasion of his privacy, is rejected, as the privacy expec-
tation is less at the border than it is in the interior, id., at 538, and
this Court has long recognized that automobiles seeking entry into this
country may be searched, see Carroll v. United States, 267 U. S. 132,
154. And while the Fourth Amendment “protects property as well as
privacy,” Soldal v. Cook County, 506 U. S. 56, 62, the interference with
a motorist’s possessory interest in his gas tank is justified by the Gov-
ernment’s paramount interest in protecting the border. Thus, the Gov-
ernment’s authority to conduct suspicionless inspections at the border

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150 UNITED STATES v. FLORES-MONTANO
Opinion of the Court
includes the authority to remove, disassemble, and reassemble a vehi-
cle’s fuel tank. Pp. 152–156.
Reversed and remanded.
Rehnquist, C. J., delivered the opinion for a unanimous Court.
Breyer, J., filed a concurring opinion, post, p. 156.
Lisa S. Blatt argued the cause for the United States.
With her on the briefs were Solicitor General Olson, As-
sistant Attorney General Wray, Deputy Solicitor General
Dreeben, Daniel S. Goodman, and Alfonso Robles.
Steven F. Hubachek, by appointment of the Court, 540
U. S. 1043, argued the cause for respondent. With him on
the brief were Vincent J. Brunkow and John C. Lemon.*
Chief Justice Rehnquist delivered the opinion of the
Court.
Customs officials seized 37 kilograms—a little more than
81 pounds—of marijuana from respondent Manuel Flores-
Montano’s gas tank at the international border. The Court
of Appeals for the Ninth Circuit, relying on an earlier de-
cision by a divided panel of that court, United States v.
Molina-Tarazon, 279 F. 3d 709 (2002), held that the Fourth
Amendment forbade the fuel tank search absent reasonable
suspicion. No. 02–50306, 2003 WL 22410705 (Mar. 14, 2003).
We hold that the search in question did not require reason-
able suspicion.
Respondent, driving a 1987 Ford Taurus station wagon,
attempted to enter the United States at the Otay Mesa Port
of Entry in southern California. A customs inspector con-
ducted an inspection of the station wagon, and requested re-
spondent to leave the vehicle. The vehicle was then taken
to a secondary inspection station.
*Daniel J. Popeo and Richard A. Samp filed a brief for the Washington
Legal Foundation et al. as amici curiae urging reversal.
John Wesley Hall, Jr., David M. Siegel, and Lisa B. Kemler filed a
brief for the National Association of Criminal Defense Lawyers as amicus
curiae urging affirmance.

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151 Cite as: 541 U. S. 149 (2004)
Opinion of the Court
At the secondary station, a second customs inspector in-
spected the gas tank by tapping it, and noted that the tank
sounded solid. Subsequently, the inspector requested a me-
chanic under contract with Customs to come to the border
station to remove the tank. Within 20 to 30 minutes, the
mechanic arrived. He raised the car on a hydraulic lift, loos-
ened the straps and unscrewed the bolts holding the gas tank
to the undercarriage of the vehicle, and then disconnected
some hoses and electrical connections. After the gas tank
was removed, the inspector hammered off bondo (a putty-like
hardening substance that is used to seal openings) from the
top of the gas tank. The inspector opened an access plate
underneath the bondo and found 37 kilograms of marijuana
bricks. The process took 15 to 25 minutes.
A grand jury for the Southern District of California in-
dicted respondent on one count of unlawfully importing mari-
juana, in violation of 21 U. S. C. § 952, and one count of pos-
session of marijuana with intent to distribute, in violation of
§ 841(a)(1). Relying on Molina-Tarazon, respondent filed a
motion to suppress the marijuana recovered from the gas
tank. In Molina-Tarazon, a divided panel of the Court of
Appeals held, inter alia, that removal of a gas tank requires
reasonable suspicion in order to be consistent with the
Fourth Amendment. 279 F. 3d, at 717.
The Government advised the District Court that it was
not relying on reasonable suspicion as a basis for deny-
ing respondent’s suppression motion, but that it believed
Molina-Tarazon was wrongly decided. The District Court,
relying on Molina-Tarazon, held that reasonable suspicion
was required to justify the search and, accordingly, granted
respondent’s motion to suppress. The Court of Appeals,
citing Molina-Tarazon, summarily affirmed the District
Court’s judgment. No. 02–50306, 2003 WL 22410705 (CA9,
Mar. 14, 2003). We granted certiorari, 540 U. S. 945 (2003),
and now reverse.

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152 UNITED STATES v. FLORES-MONTANO
Opinion of the Court
In Molina-Tarazon, the Court of Appeals decided a case
presenting similar facts to the one at bar. It asked
“whether [the removal and dismantling of the defendant’s
fuel tank] is a ‘routine’ border search for which no suspicion
whatsoever is required.” 279 F. 3d, at 711. The Court of
Appeals stated that “[i]n order to conduct a search that goes
beyond the routine, an inspector must have reasonable suspi-
cion,” and the “critical factor” in determining whether a
search is “routine” is the “degree of intrusiveness.” Id., at
712–713.
The Court of Appeals seized on language from our opinion
in United States v. Montoya de Hernandez, 473 U. S. 531
(1985), in which we used the word “routine” as a descriptive
term in discussing border searches. Id., at 538 (“Routine
searches of the persons and effects of entrants are not sub-
ject to any requirement of reasonable suspicion, probable
cause, or warrant”); id., at 541, n. 4 (“Because the issues are
not presented today we suggest no view on what level of
suspicion, if any, is required for nonroutine border searches
such as strip, body-cavity, or involuntary x-ray searches”).
The Court of Appeals took the term “routine,” fashioned a
new balancing test, and extended it to searches of vehicles.
But the reasons that might support a requirement of some
level of suspicion in the case of highly intrusive searches of
the person—dignity and privacy interests of the person
being searched—simply do not carry over to vehicles. Com-
plex balancing tests to determine what is a “routine” search
of a vehicle, as opposed to a more “intrusive” search of a
person, have no place in border searches of vehicles.
The Government’s interest in preventing the entry of
unwanted persons and effects is at its zenith at the inter-
national border. Time and again, we have stated that
“searches made at the border, pursuant to the longstanding
right of the sovereign to protect itself by stopping and exam-
ining persons and property crossing into this country, are
reasonable simply by virtue of the fact that they occur at the

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Opinion of the Court
border.” United States v. Ramsey, 431 U. S. 606, 616 (1977).
Congress, since the beginning of our Government, “has
granted the Executive plenary authority to conduct routine
searches and seizures at the border, without probable cause
or a warrant, in order to regulate the collection of duties and
to prevent the introduction of contraband into this country.”
Montoya de Hernandez, supra, at 537 (citing Ramsey, supra,
at 616–617 (citing Act of July 31, 1789, ch. 5, 1 Stat. 29)).
The modern statute that authorized the search in this case,
46 Stat. 747, 19 U. S. C. § 1581(a),1 derived from a statute
passed by the First Congress, the Act of Aug. 4, 1790, ch. 35,
§ 31, 1 Stat. 164, see United States v. Villamonte-Marquez,
462 U. S. 579, 584 (1983), and reflects the “impressive histori-
cal pedigree” of the Government’s power and interest, id., at
585. It is axiomatic that the United States, as sovereign,
has the inherent authority to protect, and a paramount inter-
est in protecting, its territorial integrity.
That interest in protecting the borders is illustrated in this
case by the evidence that smugglers frequently attempt to
penetrate our borders with contraband secreted in their au-
tomobiles’ fuel tank. Over the past 51 ⁄ 2 fiscal years, there
have been 18,788 vehicle drug seizures at the southern Cali-
fornia ports of entry. App. to Pet. for Cert. 12a. Of those
18,788, gas tank drug seizures have accounted for 4,619 of
the vehicle drug seizures, or approximately 25%. Ibid. In
addition, instances of persons smuggled in and around gas
tank compartments are discovered at the ports of entry of
1 Section 1581(a) provides:
“Any officer of the customs may at any time go on board of any vessel
or vehicle at any place in the United States or within the customs waters
or, as he may be authorized, within a customs-enforcement area estab-
lished under the Anti-Smuggling Act, or at any other authorized place,
without as well as within his district, and examine the manifest and other
documents and papers and examine, inspect, and search the vessel or vehi-
cle and every part thereof and any person, trunk, package, or cargo on
board, and to this end may hail and stop such vessel or vehicle, and use
all necessary force to compel compliance.”

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154 UNITED STATES v. FLORES-MONTANO
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San Ysidro and Otay Mesa at a rate averaging 1 approxi-
mately every 10 days. Id., at 16a.
Respondent asserts two main arguments with respect to
his Fourth Amendment interests. First, he urges that he
has a privacy interest in his fuel tank, and that the suspicion-
less disassembly of his tank is an invasion of his privacy.
But on many occasions, we have noted that the expectation
of privacy is less at the border than it is in the interior.
Montoya de Hernandez, supra, at 538. We have long recog-
nized that automobiles seeking entry into this country may
be searched. See Carroll v. United States, 267 U. S. 132,
154 (1925) (“Travellers may be so stopped in crossing an in-
ternational boundary because of national self protection rea-
sonably requiring one entering the country to identify him-
self as entitled to come in, and his belongings as effects
which may be lawfully brought in”). It is difficult to imag-
ine how the search of a gas tank, which should be solely a
repository for fuel, could be more of an invasion of privacy
than the search of the automobile’s passenger compartment.
Second, respondent argues that the Fourth Amendment
“protects property as well as privacy,” Soldal v. Cook
County, 506 U. S. 56, 62 (1992), and that the disassembly and
reassembly of his gas tank is a significant deprivation of his
property interest because it may damage the vehicle. He
does not, and on the record cannot, truly contend that the
procedure of removal, disassembly, and reassembly of the
fuel tank in this case or any other has resulted in serious
damage to, or destruction of, the property.2 According to
2 Respondent’s reliance on cases involving exploratory drilling searches
is misplaced. See United States v. Rivas, 157 F. 3d 364 (CA5 1998) (drill-
ing into body of trailer required reasonable suspicion); United States v.
Robles, 45 F. 3d 1 (CA1 1995) (drilling into machine part required reason-
able suspicion); United States v. Carreon, 872 F. 2d 1436 (CA10 1989) (drill-
ing into camper required reasonable suspicion). We have no reason at
this time to pass on the reasonableness of drilling, but simply note the
obvious factual difference that this case involves the procedure of removal,
disassembly, and reassembly of a fuel tank, rather than potentially de-

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Opinion of the Court
the Government, for example, in fiscal year 2003, 348 gas
tank searches conducted along the southern border were
negative (i. e., no contraband was found), the gas tanks were
reassembled, and the vehicles continued their entry into the
United States without incident. Brief for United States 31.
Respondent cites not a single accident involving the vehi-
cle or motorist in the many thousands of gas tank disassem-
blies that have occurred at the border. A gas tank search
involves a brief procedure that can be reversed without
damaging the safety or operation of the vehicle. If damage
to a vehicle were to occur, the motorist might be entitled
to recovery. See, e. g., 31 U. S. C. § 3723; 19 U. S. C. § 1630.
While the interference with a motorist’s possessory interest
is not insignificant when the Government removes, disassem-
bles, and reassembles his gas tank, it nevertheless is justified
by the Government’s paramount interest in protecting the
border.3
For the reasons stated, we conclude that the Government’s
authority to conduct suspicionless inspections at the border
includes the authority to remove, disassemble, and reassem-
ble a vehicle’s fuel tank. While it may be true that some
structive drilling. We again leave open the question “whether, and under
what circumstances, a border search might be deemed ‘unreasonable’ be-
cause of the particularly offensive manner in which it is carried out.”
United States v. Ramsey, 431 U. S. 606, 618, n. 13 (1977).
3 Respondent also argued that he has some sort of Fourth Amendment
right not to be subject to delay at the international border and that the
need for the use of specialized labor, as well as the hour actual delay here
and the potential for even greater delay for reassembly are an invasion of
that right. Respondent points to no cases indicating the Fourth Amend-
ment shields entrants from inconvenience or delay at the international
border.
The procedure in this case took about an hour (including the wait for
the mechanic). At oral argument, the Government advised us that, de-
pending on the type of car, a search involving the disassembly and reas-
sembly of a gas tank may take one to two hours. Tr. of Oral Arg. 10.
We think it clear that delays of one to two hours at international borders
are to be expected.

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156 UNITED STATES v. FLORES-MONTANO
Breyer, J., concurring
searches of property are so destructive as to require a differ-
ent result, this was not one of them. The judgment of the
United States Court of Appeals for the Ninth Circuit is
therefore reversed, and the case is remanded for further pro-
ceedings consistent with this opinion.
It is so ordered.
Justice Breyer, concurring.
I join the Court’s opinion in full. I also note that Customs
keeps track of the border searches its agents conduct, includ-
ing the reasons for the searches. Tr. of Oral Arg. 53–54.
This administrative process should help minimize concerns
that gas tank searches might be undertaken in an abusive
manner.