                   FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,               
                 Plaintiff-Appellee,
                                               Nos. 08-50114
                v.                                  08-50118
DANIEL GUZMAN-PADILLA,
             Defendant-Appellant,
                                               D.C. No.
                                              CR-07-695-IEG
               and
                                                OPINION
JUAN VASQUEZ-ROSALES,
             Defendant-Appellant.
                                        
        Appeals from the United States District Court
           for the Southern District of California
      Irma E. Gonzales, Chief District Judge, Presiding

                    Argued and Submitted
             April 7, 2009—Pasadena, California

                      Filed July 23, 2009

     Before: Harry Pregerson and David R. Thompson,
     Circuit Judges, and Jeremy Fogel,* District Judge.

                    Opinion by Judge Fogel




  *The Honorable Jeremy Fogel, United States District Judge for the
Northern District of California, sitting by designation.

                               9427
              UNITED STATES v. GUZMAN-PADILLA          9431




                        COUNSEL

Shaun Khojayan (argued) and Janet C. Tung, San Diego, Cali-
fornia, for the appellants.

Mark R. Rehe (argued), San Diego, California, for the appel-
lee.
9432           UNITED STATES v. GUZMAN-PADILLA
                          OPINION

FOGEL, District Judge:

   Daniel Guzman-Padilla (“Guzman”) and Juan Vasquez-
Rosales (“Vasquez”) (collectively, “Appellants”) appeal the
district court’s denial of their motions to suppress evidence
discovered during a stop and search of their vehicle by U.S.
Border Patrol agents on February 4, 2007 near the border
between the United States and Mexico. Believing that Appel-
lants’ vehicle recently had crossed the border and was carry-
ing contraband, Border Patrol Agent Marc Battaglini
instructed that a controlled tire deflation device (“CTDD”) be
deployed in the vehicle’s path. As intended, all four of the
vehicle’s tires were deflated within approximately a half-mile,
and the vehicle pulled to the side of the highway.

   In the district court, Appellants argued that suppression was
required because the use of the CTDD converted the stop into
an “arrest” for which the requisite probable cause was lack-
ing, and because the unannounced use of the device amounted
to excessive force. The government argued, and the district
court agreed, that the stop was an investigative detention
authorized under the rubric of Terry v. Ohio, 392 U.S. 1
(1968), and that it was conducted in a reasonable manner. The
district court also rejected Guzman’s request under Brady v.
Maryland, 373 U.S. 83 (1963), for production of the Border
Patrol’s Policy Manual governing the use of CTDDs, finding
that the manual was immaterial to the question of Fourth
Amendment reasonableness.

   Vasquez entered a guilty plea while reserving his right to
appeal the court’s denial of his motion to suppress. Guzman
was found guilty following a bench trial on stipulated facts.
In these consolidated appeals, the parties renew the conten-
tions they made in the district court, but the government also
contends that the stop was justified under the border search
doctrine. We agree that the stop of Appellants’ vehicle was a
               UNITED STATES v. GUZMAN-PADILLA              9433
valid seizure incident to an extended border search, and that
the force used to effect the stop was not excessive. We there-
fore affirm.

                      BACKGROUND

   Our decision today is informed to a significant degree by
the unique geographic and topographical features of the
southeast corner of Imperial County, California, where the
events underlying these appeals occurred. Of particular
importance are two valleys called the A-7 and the Buttercup.
Each consists of a rugged floor lined by tall sand dunes, many
of which themselves contain interior valleys or depressions.
Both valleys run uninterrupted from Mexico to a public camp-
site on the United States side of the border, where they con-
verge. From that point, a paved road leads to Interstate 8.
Border Patrol Agent Battaglini, a member of the Smuggler
Targeting Action Team (“STAT”) who for six years has been
deployed extensively in this part of the Imperial Sand Dunes,
is intimately familiar with the local terrain. In his experience
patrolling the area in a variety of transports ranging from all-
terrain vehicles to Ford Expeditions such as the one driven by
Appellants on the day in question, substantial vehicular
modifications—such as elevated suspension systems or spe-
cial “paddle tires”—are necessary to cross the dunes that abut
either valley. Thus, “unmodified” four-wheel-drive vehicles
are confined to the valley floor, which forms an unbroken
conduit from Mexico to the United States. The valleys also
converge in a manner that affords observers at the Buttercup
Campground an unobstructed view of exiting dune traffic. As
such, the location of the campground, which is less than two
miles from the border, corresponds to a natural choke point
for the interception of illicit goods or persons. The flow of
such goods and persons is considerable: at the time of the
events in question, Battaglini had been involved personally in
the arrest of fifty to sixty drug or alien smugglers in the area.

  At about 8:30 AM on February 4, 2007, Battaglini and fel-
low Border Patrol Agent Michael Harrington began their sur-
9434           UNITED STATES v. GUZMAN-PADILLA
veillance duty at the Buttercup Campground, training their
sights on the outlets of the two valleys. Several times during
the day, agents from the nearby Yuma Border Patrol Station
drove into the A-7 Valley and reported no unusual vehicle
sightings. The trickle of morning recreational traffic ebbed by
early afternoon—likely because it was Super Bowl Sunday—
and by mid-afternoon the dunes were empty. It was under
these conditions that Appellants’ white Ford Expedition
emerged from the A-7 Valley at approximately 3:30 PM.
When first sighted, the vehicle was approximately one and a
half miles from the border. From a distance of about a half-
mile, Battaglini made several observations. First, he consid-
ered the vehicle’s speed—approximately twenty to twenty-
five miles per hour—unusually fast for the terrain; he later
testified that five miles per hour would be an appropriate
speed to avoid “beating up” an ordinary four-wheel-drive
vehicle. Second, he noticed that the vehicle bore no apparent
modifications that would have permitted it to enter the valley
from anywhere but its Mexican entrance to the south. Third,
he observed that the vehicle lacked the orange safety flag and
recreational permit required by the federal agency that man-
ages the Imperial Dunes, and was driving in a straight path
uncharacteristic of recreational use.

   Battaglini radioed nearby members of the STAT Unit and
informed them of the approaching vehicle. Soon thereafter,
the Expedition drove directly past the agents’ unmarked patrol
cars, affording the agents a view into its fully enclosed inte-
rior. Battaglini observed that the entire rear portion of the
cabin was covered by a black tarp, something which he had
seen exclusively in vehicles ultimately stopped for smuggling.
He also noted that the vehicle bore Mexican license plates, a
feature he considered rare in the Imperial Sand Dunes. Bat-
taglini watched as the vehicle proceeded toward the highway,
rolling through a stop sign, and, after passing the desired
entrance ramp, reversing course in the middle of the road.

  Collectively, Battaglini’s observations caused him to feel
certain that the vehicle was smuggling drugs, aliens, or other
               UNITED STATES v. GUZMAN-PADILLA              9435
illicit goods, and he determined to stop it using a CTDD. The
device consists of an accordion-like tray containing small,
hollow steel tubes that puncture the tires of a passing vehicle
and cause a gradual release of air. The vehicle then ordinarily
may travel for approximately a quarter to a half of a mile
before complete deflation occurs. Battaglini testified that the
Border Patrol uses CTDDs in three instances: where a vehicle
(1) has made a “confirmed illegal entry” from Mexico; (2) has
been observed taking on or discharging narcotics or illegal
aliens; or (3) fails to yield during an attempted stop, giving
rise to pursuit. Battaglini also testified that the Border Patrol
does not use CTDDs in the vicinity of bridges, hills, curves
in the roadway, or metropolitan areas, or in the presence of
heavy traffic. He testified that several agents typically coordi-
nate with one another during deployment of a CTDD to keep
other motor traffic away from both the suspect vehicle and the
device. He explained that the Border Patrol uses CTDDs as a
first resort because smugglers rarely yield to lights or sirens
and frequently engage in desperate attempts to escape appre-
hension, including by crossing freeway medians, driving into
oncoming traffic, and leading officers on high-speed pursuits.
He testified that in multiple cases, the use of lights and sirens
caused erratic behavior that resulted in the deaths of innocent
bystanders.

   Before authorizing deployment of the CTDD, Battaglini
conferred with his supervisor by radio, confirming, based on
the circumstances of its emergence from the A-7 Valley, that
Appellants’ vehicle had made an illegal entry. Battaglini and
Harrington followed the vehicle for approximately ten miles
before the device was deployed by another member of the
STAT Unit. Presumably because it was the afternoon of Super
Bowl Sunday, highway traffic was light, and the agents kept
what little traffic there was away from the zone of deploy-
ment. The stretch of road where the device was deployed was
open and flat, with no nearby structures, hills, or other haz-
ards. After Appellants’ vehicle passed over the spike strip,
both agents activated their lights and sirens. The Expedition
9436           UNITED STATES v. GUZMAN-PADILLA
proceeded approximately a half-mile before its tires went flat
and it pulled to the side of the road.

   As Battaglini stepped out of his vehicle, the door of the
Expedition swung open and Vasquez began to exit. At that
moment, Battaglini encountered a strong odor of marijuana.
He approached the vehicle with his weapon drawn and
ordered Vasquez to remain inside. When he reached the vehi-
cle, he removed Vasquez, handcuffed him, ordered him onto
his knees, and patted him down. Agent Harrington restrained
Guzman. The agents then discovered approximately 479.95
kilograms (1,058.1 pounds) of marijuana, which had an esti-
mated retail value of $670,000 in Imperial County.

   Vasquez and Guzman were indicted on charges of posses-
sion with intent to distribute 100 kilograms or more of mari-
juana. The district court held three days of evidentiary
hearings on their motions to suppress, during which the gov-
ernment relied exclusively on the testimony of Battaglini,
while the defense offered a declaration by Vasquez and the
testimony of Robert Davidson, a recreational user of the
Imperial Sand Dunes who visits the area several times a year.
When the district court denied the motions to suppress, the
defense moved for reconsideration and offered the declaration
of Jack Smith, a use-of-force expert who stated in essence that
tire deflation devices are dangerous and unjustified under the
circumstances that were present. Unpersuaded by Smith’s
declaration, the district court reaffirmed its prior ruling.

                         ANALYSIS

   [1] When a vehicle is stopped by law enforcement, all of
its occupants are “seized” for Fourth Amendment purposes.
Brendlin v. California, 127 S.Ct. 2400, 2406-08 (2007). In
determining whether such a seizure comports with the Fourth
Amendment, “the touchstone . . . is reasonableness.” United
States v. Kriesel, 508 F.3d 941, 947 (9th Cir. 2007) (quoting
Samson v. California, 547 U.S. 843, 855 n.4 (2006)). The
               UNITED STATES v. GUZMAN-PADILLA               9437
“general Fourth Amendment approach” requires courts to
examine the totality of the circumstances to determine
whether a search or seizure is reasonable. United States v.
Knights, 534 U.S. 112, 118 (2001) (citation omitted).

   The first aspect of the reasonableness inquiry concerns the
level of suspicion that the government’s agents must possess
to justify their intrusions. Without such justification, a seizure
is per se unreasonable. Traditionally, all Fourth Amendment
“seizures” constituted “arrests” and therefore required proba-
ble cause. Dunaway v. New York, 442 U.S. 200, 208-09
(1979). Departing from the traditional rule, the Supreme
Court in Terry v. Ohio, 392 U.S. 1 (1968), “recognized an
exception” to the probable cause requirement for police
encounters that were “much less severe [in their intrusiveness]
than . . . traditional ‘arrests,’ ” holding that reasonable suspi-
cion would suffice. Dunaway, 442 U.S. at 209. The reason-
able suspicion/probable cause framework remains binary in
nature, see Morgan v. Woessner, 997 F.2d 1244, 1252 (9th
Cir. 1993), with the proviso that under the border search doc-
trine, law enforcement may conduct certain searches and sei-
zures at the border without any suspicion, United States v.
Alfonso, 759 F.2d 728, 733-34 (9th Cir. 1985).

    The second aspect of the inquiry concerns the manner in
which a seizure is conducted—typically whether law enforce-
ment used excessive force. See Graham v. Connor, 490 U.S.
386, 394-95 (1989) (“[T]he ‘reasonableness’ of a particular
seizure depends not only on when it is made, but also on how
it is carried out.” (emphasis removed)). “[A]ll claims that law
enforcement officers have used excessive force—deadly or
not—in the course of an arrest, investigatory stop, or other
‘seizure’ of a free citizen should be analyzed under the Fourth
Amendment and its ‘reasonableness’ standard . . . . ” Id.
(emphasis removed). In so doing, courts consider the totality
of the circumstances, Samson, 547 U.S. at 848, and “balance
the nature and quality of the intrusion on the individual’s
Fourth Amendment interests against the importance of the
9438              UNITED STATES v. GUZMAN-PADILLA
governmental interests alleged to justify the intrusion.” Scott
v. Harris, 550 U.S. 372, 383 (2007) (citation omitted).

   In accordance with these principles, we must determine as
a threshold matter what level of suspicion was required to ren-
der the Border Patrol agents’ stop of Appellants’ vehicle “rea-
sonable.” The possible justifications for intrusion range from
no suspicion if the seizure was incident to a “border search”
or its functional equivalent, to “reasonable suspicion” if the
seizure was incident to an “extended border search,” to proba-
ble cause if the seizure nonetheless constituted an “arrest.”1
Next, we must decide whether the manner in which the agents
effected the stop was excessively forceful and therefore
unreasonable.
  1
    Appellants contend that the government waived the border search argu-
ment by failing to present it to the district court. While matters not pre-
sented to the trial court generally may not be raised for the first time on
appeal, United States v. Flores-Payon, 942 F.2d 556, 558 (9th Cir. 1991),
“the Supreme Court has made clear [that] it is claims that are deemed
waived or forfeited, not arguments.” United States v. Pallares-Galan, 359
F.3d 1088, 1095 (9th Cir. 2004) (citing Lebron v. Nat’l Railroad Passen-
ger Corp., 513 U.S. 374, 378-79 (1995)); see also Lebron, 513 U.S. at
377-80; Yee v. Escondido, 503 U.S. 519, 534 (1992) (“Once a federal
claim is properly presented, a party can make any argument in support of
that claim; parties are not limited to the precise arguments they made
below.”).
   Here, while the government made no mention of border searches in the
district court, it consistently has claimed that the seizure of Appellants’
vehicle did not require probable cause. The border search justification is
merely an additional argument raised in support of that claim. Moreover,
all of the factual predicates of a border search were fully litigated below.
Accordingly, we may consider the government’s argument that the seizure
falls within the border search rubric, and we must determine only whether
the record supports the government’s legal position.
               UNITED STATES v. GUZMAN-PADILLA             9439
 I.   SEARCHES AND SEIZURES AT THE BORDER

                   A.   General Principles

   [2] The legality of a border search is reviewed de novo.
United States v. Romm, 455 F.3d 990, 996 (9th Cir. 2006).
The border search doctrine is a partial exception to the Fourth
Amendment’s limitations on searches and seizures. United
States v. Ramsey, 431 U.S. 606, 616-19 (1977). “The primary
purpose of a border search is to seize contraband property
sought to be brought into the country.” Alfonso, 759 F.2d at
733 (citing Alexander v. United States, 362 F.2d 379, 382 (9th
Cir. 1966)). Accordingly, at least with respect to the Fourth
Amendment’s suspicion requirements, a routine border search
“is by its very nature reasonable.” United States v. Dobson,
781 F.2d 1374, 1376 (9th Cir. 1986).

   [3] Border searches need not occur at an actual border, but
may take place at the “functional equivalent” of a border, or
at an “extended” border. United States v. Cardona, 769 F.2d
625, 628 (9th Cir. 1985); see also Almeida-Sanchez v. United
States, 413 U.S. 266, 272 (1973); United States v. Duncan,
693 F.2d 971, 977 (9th Cir. 1982). Searches conducted at the
functional equivalent of a border require no suspicion, pro-
vided that they are not “unreasonably intrusive.” United
States v. Seljan, 547 F.3d 993, 1002-03 (9th Cir. 2008).
Extended border searches, which “occur after the actual entry
has been effected and intrude more on an individual’s normal
expectation of privacy[,] . . . must be justified by ‘reasonable
suspicion’ that the subject of the search was involved in crim-
inal activity.” Alfonso, 759 F.2d at 734 (citing United States
v. Caicedo-Guarnizo, 723 F.2d 1420, 1422-23 (9th Cir.
1984)); see also United States v. Garcia, 672 F.2d 1349, 1367
(11th Cir. 1982). Either type of border search requires that
law enforcement possess a “reasonable certainty” that a bor-
der has been crossed, either by the vehicle in question, or by
contraband suspected to be within the vehicle. See United
States v. Sahanaja, 430 F.3d 1049, 1053-54 (9th Cir. 2005).
9440           UNITED STATES v. GUZMAN-PADILLA
   B.   Classification of the subject search and seizure

   The government argues that the search and seizure at issue
here occurred at the functional equivalent of the border. We
are inclined to disagree. Our cases are consistent with the
Fifth Circuit’s observation that “[t]he main difference
between the functional equivalent of the 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.” United States v. Niver, 689 F.2d 520, 526
(5th Cir. 1982); see United States v. Abbouchi, 502 F.3d 850,
855-56 (9th Cir. 2007) (holding that centralized parcel pro-
cessing hub provided the “last practicable opportunity” for
customs agents to inspect foreign-directed packages, notwith-
standing the possibility that the packages might stop at other
points before leaving the country); United States v. Potter,
552 F.2d 901, 907 (9th Cir. 1977) (holding that the first prac-
ticable opportunity to conduct a search of an international
flight is the first domestic point of arrival). Here, although
Appellants’ vehicle passed the agents’ unmarked patrol cars
at approximately five to ten miles per hour upon exiting the
Buttercup Campground, the agents followed the vehicle onto
the highway for nearly ten miles. While it may well have been
inadvisable to stop the vehicle before it had passed several
points at which suspects frequently flee in a dangerous man-
ner towards Mexico when pursued by law enforcement, we
doubt whether it was wholly “impracticable” for the agents to
do so, particularly since the situation at hand hardly appears
to have been unique.

   By contrast, the extended border search doctrine clearly
contemplates the situation we confront here. “Extended bor-
der searches are typically separated from the border by ‘a
greater spatial and temporal distance’ from the actual border
than searches at the functional equivalent of the border,”
Abbouchi, 502 F.3d at 855 (citing Cardona, 769 F.2d at 628),
and encompass a wide range of spatial and temporal relation-
ships with the border, see, e.g., Alfonso, 759 F.2d at 734-35
               UNITED STATES v. GUZMAN-PADILLA              9441
(upholding extended border search of boat thirty-six hours
after it crossed the border); United States v. Martinez, 481
F.2d 214 (5th Cir. 1973) (finding that search conducted one-
hundred-fifty miles from the border and one-hundred-forty-
two hours after a border crossing was an extended border
search); Rodriquez-Gonzalez v. United States, 378 F.2d 256
(9th Cir. 1967) (finding that search conducted fifteen hours
after a border crossing at a distance of twenty miles from the
border was an extended border search). The flexibility inher-
ent in the extended border search doctrine reflects a balancing
of the individual’s right to freedom from arbitrary intrusions
against the “myriad difficulties facing customs and immigra-
tion officials who are charged with the enforcement of smug-
gling and immigration laws.” United States v. Richards, 638
F.2d 765, 771 (1981). That flexibility has led us to define an
extended border search as any “search away from the border
where entry is not apparent,” United States v. Corral-
Villavicencio, 753 F.2d 785, 788 (9th Cir. 1985) (emphasis
added), but where the dual requirements of reasonable cer-
tainty of a recent border crossing and reasonable suspicion of
criminal activity are satisfied. Sahanaja, 430 F.3d at 1053-54.

   There are two reasons why we need not decide precisely
what type of border search occurred here. First, the seizure
required to effect the search of Appellants’ vehicle clearly
was more than a “routine” search of the kind permissible in
the absence of suspicion. Highly intrusive searches require
reasonable suspicion, even if they are conducted at the func-
tional equivalent of the border. United States v. Flores-
Montano, 541 U.S. 149, 152 (2004) (emphasis added); see
also Seljan, 547 F.3d at 1001-02. In assessing whether a vehi-
cle search is sufficiently intrusive to require reasonable suspi-
cion, we focus on “two main issues: (1) Did the search
damage the vehicle in a manner that affected the vehicle’s
safety or operability, and (2) Was the search conducted in a
particularly offensive manner.” United States v. Cortez-
Rivera, 454 F.3d 1038, 1042 (9th Cir. 2006). The damage fac-
tor alone is decisive here because Appellants’ vehicle was
9442            UNITED STATES v. GUZMAN-PADILLA
rendered inoperable when its tires were destroyed in the
course of the seizure. Cf. Flores-Montano, 541 U.S. at 155-56
(authorizing suspicionless disassembly and reassembly of gas
tank); Cortez-Rivera, 454 F.3d at 1042-43 (authorizing cus-
toms agents to pry open quarter of vehicle’s interior door
panel without particularized suspicion); United States v.
Cortez-Rocha, 394 F.3d 1115, 1125 (9th Cir. 2005) (authoriz-
ing suspicionless slashing of spare tire to search for contra-
band); United States v. Chaudhry, 424 F.3d 1051, 1053-55
(9th Cir. 2005) (authorizing suspicionless exploratory drilling
of small hole in truck bed). Thus, even if the seizure were
deemed incident to a functional-equivalent border search, the
requirements of an extended border search—reasonable cer-
tainty of a border crossing and reasonable suspicion of crimi-
nal activity—would have to be satisfied.

   [4] Second, as we explain below, and as Appellants effec-
tively concede, the presence of reasonable suspicion is
beyond dispute in this case. We are constitutionally forbidden
from issuing advisory opinions, and we decline to decide a
“dispute over whether or not a particular search may be con-
ducted in the absence of any suspicion[,] [where that dispute]
is an entirely fictional construct.” Chaudhry, 424 F.3d at
1054-55 (B. Fletcher, J., specially concurring) (emphasis
removed). Accordingly, in this instance the government must
demonstrate that its agents possessed a reasonable certainty
that a border crossing had occurred and reasonable suspicion
that criminal activity was afoot. Because the subject search
appears to fit most comfortably within the extended border
search doctrine, we will evaluate it as such for the sake of
clarity.

           C.    Reasonable certainty of crossing

  [5] We assess the existence of reasonable certainty of a bor-
der crossing by examining “the totality of the surrounding cir-
cumstances, including the time and distance elapsed [from the
border] as well as the manner and extent of surveillance.”
               UNITED STATES v. GUZMAN-PADILLA              9443
Alexander, 362 F.2d at 382. These circumstances must be
“such as to convince the fact finder with reasonable certainty
that any contraband which might be found in or on the vehicle
at the time of search was aboard the vehicle at the time of
entry into the jurisdiction of the United States.” Id. The issue
is “not . . . whether the vessel [or vehicle] actually crossed
into the United States territory, but whether the searching . . .
officers were reasonably certain that it did.” Tilton, 534 F.2d
at 1366. Thus, an agent or officer need not have observed the
crossing. United States v. Bennett, 363 F.3d 947, 950 (9th Cir.
2004); Dobson, 781 F.2d at 1376; United States v. Stanley,
545 F.2d 661, 666 n.6 (9th Cir. 1976). As a corollary, while
“continuity of surveillance over the subject of the search is a
factor in determining identity,” Alfonso, 759 F.2d at 735 (cit-
ing Caicedo-Guarnizo, 723 F.2d at 1422), it is not required,
see Potter, 552 F.2d at 907; United States v. Driscoll, 632
F.2d 737, 739 (9th Cir. 1980); Leeks v. United States, 356
F.2d 470, 471 (9th Cir. 1966).

   Reasonable certainty “is a higher standard than that of
probable cause, [but] it does not require knowledge beyond a
reasonable doubt.” Corral-Villavicencio, 753 F.2d at 788 (cit-
ing Kessler, 497 F.2d at 279). Rather, “the totality of the facts
and circumstances within the officers’ knowledge and of
which they have reasonably trustworthy information [must]
be sufficient in the light of their experience to warrant a firm
belief that a border crossing has occurred.” Tilton, 534 F.2d
at 1366-67 (emphasis added); see also Potter, 552 F.2d at 907
(reaffirming that absolute certainty is not required).

   Application of the extended border search doctrine may be
defeated when “conditions . . . have become so vulnerable to
change after a border crossing as to rebut any reasonable cer-
tainty that contraband later found was aboard a carrier at
entry.” Alfonso, 759 F.2d at 736. In United States v. Petersen,
473 F.2d 874 (9th Cir. 1973), for example, officers lost sight
of a vehicle for ten minutes after it crossed the border, during
which time the driver picked up two passengers. It therefore
9444           UNITED STATES v. GUZMAN-PADILLA
was not reasonably certain that the contraband ultimately
recovered was in the vehicle when it crossed the border. Id.
at 876. In United States v. Anderson, 509 F.2d 724 (9th Cir.
1975), the vehicle in question made several stops at the border
crossing, picking up and discharging passengers, one of
whom was seen retrieving a package hidden near a palm tree.
It therefore was most reasonable to infer that contraband
found in the vehicle had been retrieved from near the tree. Id.
at 726. Similarly, in United States v. Perez, 644 F.2d 1299,
1302 (9th Cir. 1981), customs agents did not see the vehicle
in question until it was in the middle of a busy town three
miles north of the border. Accordingly, there could have been
no reasonable certainty that any contraband found in the vehi-
cle had crossed the border. Id.

   [6] In the case before us, several factors appear to support
a finding of reasonable certainty. First, the outlet of the A-7
Valley, from which Battaglini first observed Appellants’ vehi-
cle, lies only one and a half miles from the Mexican border.
Second, Battaglini testified that the large dunes flanking the
valley between its origin in Mexico and its terminus in the
United States are impassible to all but specially modified
vehicles, and that Appellants’ vehicle did not appear to be
specially equipped or modified. Third, Battaglini stressed that
the absence of any reports of vehicle traffic in the A-7 by rov-
ing border patrol vehicles earlier in the day eliminated the
possibility that Appellants’ vehicle merely had lingered in the
area from the previous day. Finally, he observed that the vehi-
cle’s unusual speed and unwavering trajectory suggested the
absence of any recreational purpose.

   In the district court, the defense offered the testimony of
Robert Davidson, an off-road vehicle enthusiast who visits the
Imperial Sand Dunes several times a year. Davidson stated
that he had been able to traverse the A-7 dunes in unmodified
vehicles, but he admitted that his vehicle was fitted with
larger-than-normal tires. Davidson also indicated the exis-
tence of several alternate routes at the northern end of the A-
               UNITED STATES v. GUZMAN-PADILLA             9445
7 Valley, the availability of which might negate the inference
that a vehicle emerging from the valley at the Buttercup
Campground necessarily had traveled north from the valley’s
Mexican flank. These routes, however, either required tra-
versal of the sand dunes, were under relayed surveillance, or
had long been closed to traffic by physical barriers—all facts
known to Battaglini on the day in question. In rebuttal testi-
mony, Battaglini maintained that the dunes were impassable
to ordinary four-wheel-drive vehicles, and the district court
made an express factual finding that Battaglini’s testimony
was “much more believable and . . . based on much more
experience than [that of] Mr. Davidson, who goes out [to the
Imperial Dunes] four times a year.” The district court noted
that Battaglini was “out there every single day and has seen
hundreds . . . [and] probably thousands of vehicles.”

   [7] The evidence offered in the district court was sufficient
to establish a “reasonable certainty” that a border crossing had
occurred, such that any contraband found in Appellants’ vehi-
cle confidently could be considered to have crossed the bor-
der. That Battaglini did not see the actual crossing or maintain
continuous surveillance over the vehicle from the time of sus-
pected crossing is not determinative under our case law.
Given the unique topographical and geographic features of the
area in question, Battaglini’s “vantage point . . . enabled him
to be reasonably certain that the [vehicle] he saw came from
Mexican [territory].” Bennett, 363 F.3d at 950-51. Appellants
have identified no “defect[s] of certainty” that would defeat
such a finding, and conditions had not “become so vulnerable
to change after [the] border crossing as to rebut” the infer-
ences reasonably drawn from Battaglini’s observations. Cf.
Alfonso, 759 F.2d 736. The vehicle was spotted not in a busy
town several miles from the border, cf. Perez, 644 F.2d at
1302, but in an empty desert less than two miles from the bor-
der and accessible only through a valley originating in Mex-
ico and forming a unitary path to the observation point at
which Battaglini was stationed. There is no reason to suspect
that additional passengers or contraband were retrieved from
9446           UNITED STATES v. GUZMAN-PADILLA
this desolate, sand-swept area. Cf. Anderson, 509 F.2d at 726.
Thus, irrespective of whether Battaglini could have been
absolutely certain that the vehicle had crossed the border, as
he claims, the record supports a finding of “reasonable cer-
tainty” that a border crossing had occurred.

                 D.    Reasonable suspicion

   [8] Determinations of reasonable suspicion are reviewed de
novo, while factual findings underlying those determinations
are reviewed for clear error, giving “due weight to inferences
drawn from those facts by resident judges and local law
enforcement.” Ornelas v. United States, 517 U.S. 690, 699
(1996). “This process allows officers to draw on their own
experience and specialized training to make inferences from
and deductions about the cumulative information available to
them that ‘might well elude an untrained person.’ ” United
States v. Arvizu, 534 U.S. 266, 273 (2002) (quoting United
States v. Cortez, 449 U.S. 411, 418 (1981)). “In the context
of Border Patrol searches, the factors to be considered in
determining whether ‘reasonable suspicion’ exists to justify
stopping a vehicle include, but are not limited to: 1) character-
istics of the area; 2) proximity to the border; 3) usual patterns
of traffic and time of day; 4) previous alien or drug smuggling
in the area; 5) behavior of the driver, including ‘obvious
attempts to evade officers’; 6) appearance or behavior of pas-
sengers; 7) model and appearance of the vehicle; and, 8) offi-
cer experience.” United States v. Garcia-Barron, 116 F.3d
1305, 1307 (9th Cir. 1997) (citing United States v. Brignoni-
Ponce, 422 U.S. 873, 885 (1975)).

   The government points to the following facts to support a
finding that Battaglini’s suspicion of criminal activity was
reasonable: the area’s well-known use as a smuggling route;
the agents’ “reasonable certainty” that Appellants’ vehicle
had just crossed illegally from Mexico; the vehicle’s failure
to display the required use permit or orange recreational
safety flag; the vehicle’s Mexican plates, which Battaglini
                 UNITED STATES v. GUZMAN-PADILLA                     9447
considered rare in the dunes; the vehicle’s straight trajectory
and unusually high speed when traveling over the rough,
washboard-like road to the Buttercup Campground, and its
haste and sudden maneuvers in accessing the highway, fol-
lowed by its slow and cautious speed once on the highway;
and, finally, the covering of the rear interior compartment of
the vehicle by a black tarp even though the rear windows
already were “blacked out.”

   [9] Based on these facts, largely in the form of testimony
by Battaglini, the district court found that “there were many,
many factors that . . . could lead to only one conclusion, and
that was that this vehicle was smuggling either aliens or
drugs.” Independent of the district court’s conclusion, nearly
every one of the factors used to evaluate whether an officer
possessed the requisite degree of suspicion supports a finding
that Battaglini’s suspicion was reasonable. While Appellants
did raise a question as to whether the vehicle merely might
have made a “detour” into Mexico from one of several nearby
locations in the United States before returning through the A-
7 Valley, that suggestion is inconsistent with the totality of
the other circumstances surrounding the emergence of the
vehicle. The circumstances were more than sufficient to
“paint a picture that would create in the mind of a trained bor-
der patrol agent a reasonable suspicion that the [vehicle’s
occupants were] engaged in criminal activity.” United States
v. Franco-Munoz, 952 F.2d 1055, 1058 (9th Cir. 1991).

II.   SEIZURES INCIDENT TO BORDER SEARCHES

  Having established that the agents were entitled to conduct
an extended border search of Appellants’ vehicle, we pause to
address Appellants’ contention that the border search doctrine
has no place in assessing the reasonableness of a related
Fourth Amendment seizure, and that our Terry-stop jurispru-
dence should control.2 Appellants are correct that the govern-
  2
    Appellants also argue that the extended border search doctrine is inap-
plicable because the agents here were not “concerned with ‘sweeping in’
9448             UNITED STATES v. GUZMAN-PADILLA
ment’s success in demonstrating an entitlement to conduct a
border search does not end our inquiry, since there remains
the possibility that the incidental detention or seizure
amounted to an “arrest” requiring probable cause, or that the
manner of the detention or seizure was otherwise unreason-
able. But our cases confirm that under appropriate circum-
stances, Fourth Amendment seizures may be analyzed entirely
within the confines of the border search doctrine. See, e.g.,
United States v. Nava, 363 F.3d 942 (9th Cir. 2004); United
States v. Bravo, 295 F.3d 1002 (9th Cir. 2002); United States
v. Zaragoza, 295 F.3d 1025 (9th Cir. 2002); United States v.
Espericueta-Reyes, 631 F.2d 616 (9th Cir. 1980). Our initial
task in this case is to determine the proper legal framework
for evaluating the reasonableness of the seizure at issue.

   In United States v. Bravo, 295 F.3d 1002 (9th Cir. 2002),
we addressed the issue of whether a border-related detention
had evolved into an “arrest” requiring probable cause. The
detention occurred at a fixed border crossing and was incident
to a border search that we strongly suggested was “routine.”
Id. at 1006-08. Under those circumstances, we noted that “the
Terry-stop framework is an inexact tool for use in the context
of border stops and searches . . . [because] officials can
engage in routine searches and questioning without any suspi-
cion whatsoever.” Id. at 1011-12 n.8. Finding that “[o]ur
Terry-stop jurisprudence [was] simply less helpful than the
border search cases which we [chose to] appl[y],” we asked
“whether, under the totality of the circumstances, a reasonable
innocent person would feel free to go after questioning, or,
more specifically, whether the person would believe that he
was being subjected to ‘more than a temporary detention

accomplices of the carrier of contraband.” See United States v.
Espericueta-Reyes, 631 F.2d 616, 620 & n.4 (9th Cir. 1980). It is well set-
tled, however, that “[n]ot all extended border searches are concerned with
‘sweeping in’ ” such accomplices. Id. Indeed, this motivation scarcely has
been discussed in the numerous extended border search cases that we have
decided since Espericueta-Reyes.
               UNITED STATES v. GUZMAN-PADILLA              9449
occasioned by border crossing formalities.’ ” Id. at 1009-12 &
n.8 (citations omitted).

   While the “fit” between the Terry-stop framework and bor-
der searches undoubtedly is “imperfect,” id., the situation we
face here—a decidedly non-routine stop of an individual at a
location other than a fixed border crossing—still implicates
considerations traditionally addressed under the Terry rubric.
We therefore “use the Terry-stop cases to guide our analysis.”
Bravo, 295 F.3d at 1015 n.1 (Paez, J., dissenting). At the same
time, however, we recognize that “special rules apply at the
border.” United States v. Butler, 249 F.3d 1094, 1098 (9th
Cir. 2001); see also Nava, 363 F.3d at 946 (rejecting appel-
lant’s reliance on “numerous cases that stand for the notion
that an effective seizure by the police amounts to an arrest
requiring probable cause,” since the conduct in each of those
cases “d[id] not take place at the border”); Bravo, 295 F.3d
at 1009 (noting that because “special rules apply at the bor-
der[,] . . . . the fact that these events occurred at the border
influences our inquiry into whether a reasonable innocent per-
son would have believed that he was under arrest” (internal
quotation marks and citation omitted)); United States v. Doe,
219 F.3d 1009, 1014 (9th Cir. 2000) (“[T]he government has
more latitude to detain persons in a border-crossing con-
text.”); United States v. RRA-A, 229 F.3d 737, 743 (9th Cir.
2000) (same). Moreover, while extended border searches
“occur after the actual entry has been effected and intrude
more on an individual’s normal expectation of privacy,”
Alfonso, 759 F.2d at 734, thus implicating the Fourth Amend-
ment balance, the special rules of the border still “influence[ ]
our inquiry” into whether a particular detention constitutes a
de facto arrest, Bravo, 295 F.3d at 1009, and our Terry juris-
prudence serves as no more than a “guide.” Bearing in mind
that our analysis proceeds in the context of an extended bor-
der search, we now consider whether the February 4, 2007
stop of Appellants’ vehicle would have been authorized as an
investigative stop under Terry.
9450           UNITED STATES v. GUZMAN-PADILLA
   A.   Seizure as investigative detention versus arrest

   [10] The Supreme Court “has been careful to maintain [the]
narrow scope” of Terry’s exception to the probable cause
requirement, and has referred to Terry stops as a “sui generis
‘rubric of police conduct.’ ” Dunaway, 442 U.S. at 209-10
(quoting Terry, 392 U.S. at 20). Thus, in describing the types
of stops authorized by Terry, the Court has noted their “brief”
and “minimal[ly] intrusi[ve]” nature. Id. at 211 n.13; see also
Arizona v. Johnson, 129 S.Ct. 781, 786 (2009) (noting that
Terry authorizes a “brief detention”). Beyond this general
consideration, two specific, objectively based inquiries typi-
cally are used to determine whether a particular seizure fits
within the investigative detention framework: one inquiry is
undertaken from the perspective of the person being detained,
the other from the perspective of law enforcement. These
inquiries frequently are “fused into one analysis.” Bravo, 295
F.3d at 1011-12 n.8.

   [11] First, it is well-established that intrusive measures may
convert a stop into an arrest if the measures would cause a
reasonable person to feel that he or she will not be free to
leave after brief questioning—i.e., that indefinite custodial
detention is inevitable. Kraus v. Pierce County, 793 F.2d
1105, 1109 (9th Cir. 1986) (“[W]here force is used such that
the innocent person could reasonably have believed he was
not free to go and that he was being taken into custody indefi-
nitely, an arrest has occurred.” (emphasis added)); accord
Bravo, 295 F.3d at 1009 (“The standard for determining
whether a person is under arrest is not simply whether a per-
son believes that he is free to leave, but rather whether a rea-
sonable person would believe that he is being subjected to
more than [a] ‘temporary detention . . . .’ ” (quoting Butler,
249 F.3d at 1100)); United States v. Miles, 247 F.3d 1009,
1012 (9th Cir. 2001) (“There has been an arrest if, under the
circumstances, a reasonable person would conclude that he
was not free to leave after brief questioning.” (emphasis
added) (quoting United States v. Del Vizo, 918 F.2d 821, 824
               UNITED STATES v. GUZMAN-PADILLA                      9451
(9th Cir. 1990)). Of course, the “reasonable person” test pre-
supposes an innocent person. Florida v. Bostick, 501 U.S.
429, 438 (1991).

   [12] Second, because “[t]he purpose of a Terry stop is to
allow the officer to pursue his investigation without fear of
violence,” United States v. Taylor, 716 F.2d 701, 708 (9th Cir.
1983) (internal quotation marks and citation omitted), “we
allow intrusive and aggressive police conduct without deem-
ing it an arrest . . . when it is a reasonable response to legiti-
mate safety concerns on the part of the investigating officers.”
Miles, 247 F.3d at 1012-13 (quoting Washington v. Lambert,
98 F.3d 1181, 1186 (9th Cir. 1996)); see also Alexander v.
County of Los Angeles, 64 F.3d 1315, 1320 (9th Cir. 1995)
(“It is well settled that when an officer reasonably believes
force is necessary to protect his own safety or the safety of the
public, measures used to restrain individuals, such as stopping
them at gunpoint and handcuffing them, are reasonable” in the
course of a Terry stop). As a result, officers with a particular-
ized basis to believe that a situation may pose safety risks
may handcuff or point a gun at an individual without convert-
ing an investigative detention into an arrest. See Miles, 247
F.3d at 1013; Alexander, 64 F.3d at 1320 (holding that offi-
cers could order individuals from car at gunpoint and hand-
cuff them in the course of a Terry stop).

  The second inquiry frequently proves determinative. As the
First Circuit recognized in United States v. Acosta-Colon,
while

    [i]t is often said that an investigatory stop constitutes
    a de facto arrest when a reasonable man in the sus-
    pect’s position would have understood his situation
    . . . to be tantamount to [an] arrest[,] . . . . in a typical
    borderline case, e.g., one in which the detention at
    issue has one or two arrest-like features but other-
    wise is arguably consistent with a Terry stop, it will
    not be obvious just how the detention at issue ought
9452             UNITED STATES v. GUZMAN-PADILLA
      reasonably to have been perceived; indeed, this will
      be the central point of contention. Thus, in . . . a case
      . . . where the detention is distinguishable from, yet
      has some features normally associated with, an
      arrest[,] . . . the analysis must revert to an examina-
      tion 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 mea-
      sures used were reasonable in light of the circum-
      stances that prompted the stop or that developed
      during its course.

157 F.3d 9, 14-15 (1st Cir. 1998) (quotation marks and cita-
tions omitted). Our analysis in Miles implicitly adopts this
logic: while the officers’ conduct in Miles—approaching the
suspect with drawn weapons, ordering him to his knees, and
handcuffing him without any explanation that the detention
was “temporary”—may or may not have caused a reasonable
person to believe that he was under arrest, we focused exclu-
sively on whether the use of force was justified under the cir-
cumstances. See Miles, 247 F.3d at 1012-13. Concluding that
it was, we held that the use of force did not transform the
detention into an arrest. Id.

                B.   The February 4, 2007 stop

   [13] While anyone in Appellants’ situation would have felt
constrained to remain at the scene immediately after his or her
tires had been deflated and as agents approached the vehicle,
it does not follow that the mere use of a CTDD to stop the
vehicle would have caused an innocent person to believe that
a prolonged custodial detention amounting to an arrest was
about to occur.3 Even if he or she were aware that his or her
  3
   Appellants contend only that the use of the CTDD rendered the stop
a de facto arrest, not that other intrusive measures employed during the
stop subsequently transformed it into an arrest.
                  UNITED STATES v. GUZMAN-PADILLA                     9453
tires had been deflated intentionally4 and that the police were
in pursuit, an innocent motorist would assume that a mistake
had been made, and that the mistake could be corrected
through contact and communication with the police. Undoubt-
edly, if the police continued to exhibit signs of an intent to
arrest after interacting with the motorist, the motorist reason-
ably might believe that an arrest was in progress. But the facts
of this case simply do not reflect such a scenario, and we can-
not say that an innocent motorist necessarily would have
believed that the use of the spikes made an indefinite custo-
dial detention inevitable.

   [14] We also are persuaded by the government’s justifica-
tion for using the relatively more intrusive CTDD method to
stop the vehicle. The facts known to Battaglini suggested a
high likelihood of smuggling activity: the area is a known
smuggling hotspot; Battaglini was at least “reasonably cer-
tain” that the vehicle had made an illegal border crossing; the
vehicle had tinted windows and a tarp covering its posterior
contents; it bore no marks of recreational use and proceeded
hastily out of the dunes in a manner inconsistent with recre-
ational activity; and it abruptly adjusted its speed from exces-
sively fast in the recreational area to considerably below the
speed limit on the highway. These facts led Battaglini to clas-
sify Appellants’ approach as a “confirmed illegal entry.” As
Battaglini testified, vehicles exiting the A-7 and Buttercup
Valleys under these particular circumstances rarely have
yielded to the police and frequently have engaged in danger-
ous maneuvers that endanger innocent members of the public.
Together, these “specific . . . circumstance[s] . . . supported
a reasonable belief that the use of [force] was necessary to
carry out the legitimate purposes of the stop without exposing
law enforcement officers, the public, or the suspect[s] . . . to
an undue risk of harm.” Acosta-Colon, 157 F.3d at 19.
  4
    In the related case of United States v. Cota-Mora, which we also
decide today, the Border Patrol agent testified that he had driven uninten-
tionally over spike strips on several occasions, and that the experience was
akin to traveling over a small “bump on the road.”
9454              UNITED STATES v. GUZMAN-PADILLA
   [15] Were we faced with an ordinary vehicle seizure unre-
lated to the “myriad difficulties facing customs and immigra-
tion officials who are charged with the enforcement of
smuggling and immigration laws,” Richards, 638 F.2d at 771,
we might hesitate to classify the seizure of Appellants’ vehi-
cle as an investigative detention, given the practical reality
that the stop rendered Appellants’ vehicle inoperable until the
tires could be repaired or replaced. We have noted that the
“duration of detention is critically important” in determining
whether a stop has become an arrest, United States v. Patter-
son, 648 F.2d 625, 632 (9th Cir. 1981), and while a detention
might be said to occur only so long as law enforcement actu-
ally detains the vehicle’s occupants, the condition of their
vehicle clearly would have subjected Appellants to consider-
able delay in going about their business. Nonetheless, because
this was not an ordinary roadside vehicle stop but one autho-
rized under the border search doctrine, where the govern-
ment’s powers are at their “zenith,” Seljan, 497 F.3d at 1041
(citing Flores-Montano, 541 U.S. at 152), we are satisfied that
the potential practical implications of deploying a CTDD do
not warrant treatment of the stop as an arrest.5

                    III.   EXCESSIVE FORCE

   [16] While our determination that the use of force against
Appellants’ vehicle failed to transform the stop into an arrest
strongly suggests that the same use of force was not “exces-
sive,” we provide a brief independent discussion of Appel-
lants’ excessive force claim, which stems principally from
their contention that spike strips are dangerous and inappro-
priate for use as a first resort. “An otherwise lawful seizure
can violate the Fourth Amendment if it is executed in an
unreasonable manner.” Alverez-Tejeda, 491 F.3d 1013, 1016
  5
    It is undisputed that probable cause to conduct a full-scale search arose
at the latest when the agents encountered the smell of unburned marijuana
emanating from the vehicle. See United States v. Garcia-Rodriguez, 558
F.2d 956, 964-65 (9th Cir. 1977).
               UNITED STATES v. GUZMAN-PADILLA               9455
(9th Cir. 2007). We review de novo whether a particular
search or seizure was carried out in a reasonable manner.
Franklin v. Foxworth, 31 F.3d 873, 875 (9th Cir. 1994). “To
assess the reasonableness of th[e] conduct, [a court] must bal-
ance the nature and quality of the intrusion on the individual’s
Fourth Amendment interests against the importance of the
governmental interests alleged to justify the intrusion,”
Alverez-Tejeda, 491 F.3d at 1016 (quoting United States v.
Jacobsen, 466 U.S. 109, 125 (1984)), paying “careful atten-
tion to the facts and circumstances of each particular case,”
Graham, 490 U.S. at 396. Searches and seizures at the border
are no less subject to this balancing. See, e.g., United States
v. Des Jardins, 747 F.2d 499, 504-05 (9th Cir. 1984).

                 A.   Governmental interests

   The government’s power at the border has an “impressive
historical pedigree,” Flores-Montano, 541 U.S. at 153, stem-
ming from its dual interests in “protecting . . . its territorial
integrity,” id.; see also Seljan, 497 F.3d at 1040, and in
“stop[ping] . . . drugs before they reach[ ] their ultimate desti-
nation,” Alverez-Tejeda, 491 F.3d at 1016; see also United
States v. Cardenas, 9 F.3d 1139, 1149 (5th Cir. 1993) (“The
major impetus behind the extended border search doctrine is
‘the government interest in stopping drug traffic.’ ” (citation
omitted)). In addition, the border patrol has a critically impor-
tant interest in protecting itself and the public during stops of
suspected smugglers. As Battaglini testified in this case,
“smuggling suspects who are confronted with a show of
authority near the border often resort to desperate means to
avoid apprehension,” such as crossing freeway medians, driv-
ing into oncoming traffic, and leading officers on high-speed
chases. Appellants consistently have failed to dispute or even
acknowledge this important consideration, which weighs
heavily in favor of permitting border patrol agents to employ
non-conventional means to protect the motoring public.
9456           UNITED STATES v. GUZMAN-PADILLA
          B.   Extent and nature of the intrusion

   Notwithstanding the strength of the government’s interests,
the extent of the intrusion here should not be trivialized. In
assessing the extent to which a particular vehicle stop intrudes
upon Fourth Amendment expectations and rights, the
Supreme Court has considered the “subjective intrusion”
effected by a stop, namely, “the generating of concern or . . .
fright on the part of lawful travelers.” Mich. Dept. of State
Police v. Sitz, 496 U.S. 444, 452 (1990) (emphasis added)
(quoting United States v. Martinez-Fuerte, 428 U.S. 543, 558
(1976)). In Sitz, the Court upheld the use of fixed sobriety
checkpoints as sufficiently unintrusive to be reasonable under
the circumstances, noting that motorists (1) could see that
other vehicles were being stopped, (2) were visibly aware of
the officers’ legitimate authority, and (3) were only minimally
inconvenienced by the stops, which lasted on average twenty-
five seconds. Id. at 448-55. In contrast to the fixed check-
points approved in Sitz, the use of tire deflation devices by
roving patrols will be unexpected and “may frighten motor-
ists.” Id. at 453 (quoting Martinez-Fuerte, 428 U.S. at 558).
To some extent, the sudden deployment of tire deflation
devices also may “inflict . . . indignity and arouse . . . resent-
ment” on the part of law-abiding motorists. Cf. Bond v.
United States, 529 U.S. 334, 337 (2000) (citation omitted).
The possibility of indignation and resentment is significant
where officers use a forcible and destructive means to stop a
vehicle without first giving its driver an opportunity to submit
voluntarily to the officers’ authority. Cf. Hudson v. Michigan,
547 U.S. 586, 594 (2006) (discussing the benefits of voluntary
compliance and the avoidance of property destruction
obtained through adherence to the knock-and-announce rule).

  Other considerations, however, point towards relatively
minimal intrusiveness. First, while Appellants’ claim that the
use of a spike strip without prior warning is “the vehicular
equivalent of shooting a suspect in the leg without first say-
ing, ‘Stop, police,’ ” the Supreme Court has rejected prior
                  UNITED STATES v. GUZMAN-PADILLA                       9457
attempts to equate the application of force to vehicles with its
application to persons. See Scott, 550 U.S. at 382-83 (noting,
in response to petitioner’s argument that police car’s “bump-
ing” of his vehicle was an unconstitutional application of
deadly force akin to shooting him, that such bumping “is, in
fact, not much like a policeman’s shooting a gun so as to hit
a person” (quotation marks and citation omitted)).

   Second, the record below amply supports the district
court’s conclusion that the use of the CTDD was safe. Based
on his deployment of the device on thirty to thirty-five occa-
sions and his observation of its deployment by others on sixty
to seventy occasions, Battaglini testified that the device is
designed to and does result in a gradual release of air from the
tires, permitting a vehicle to travel approximately one half of
a mile at highway speeds before complete deflation occurs.
Battaglini knew of only one instance in which a driver lost
control, and in that case the driver swerved to avoid the
device. Battaglini also testified that the Border Patrol takes
specific precautions in using the device. For example, it does
not deploy the device in the vicinity of bridges, hills, curves
in the roadway, or in metropolitan or other heavily trafficked
areas, and multiple agents coordinate their efforts to keep
other traffic out of the way of the device as the suspect vehi-
cle approaches it.6 Lastly, Battaglini testified that on the day
in question, traffic was very light, the device was deployed
along a straight section of desert road with no nearby hazards,
and two Border Patrol vehicles, including Battaglini’s, were
  6
    Appellants’ reliance on the facts of Bublitz v. Cottey, 327 F.3d 485 (7th
Cir. 2003), is misplaced. In Bublitz, a suspect ran over a spike strip and
swerved into traffic, striking a vehicle and killing two of its occupants. Id.
at 487. Bublitz is easily distinguishable in that the officers there deployed
the spike strip in a dense metropolitan area. Battaglini testified that the
Border Patrol does not employ CTDDs in urban areas or where other
potential hazards are present, and that other traffic is held back to avoid
contact with the device and the suspect. Both precautions were taken in
this case, and the evidence overwhelmingly suggests that the absence of
injuries was anything but coincidental.
9458           UNITED STATES v. GUZMAN-PADILLA
positioned to keep any other traffic from coming into contact
with the spike strip.

   To rebut the evidence of safety, Appellants focused in the
district court on the contents of a training manual provided by
the manufacturer of the Border Patrol’s spike strips. The man-
ual indicates that the strips are designed to “stop[ ] high-speed
pursuits” and are thus for pursuit termination only. Appellants
have failed to explain, however, why the guidance in the
training manual should determine whether the device may be
used safely in other situations—particularly in situations
where its use poses inherently less danger than in a high-
speed pursuit. Appellants appear to contend that the prescrip-
tions of the Training Manual should supersede police judg-
ment as to the proper selection of the means to meet a threat,
but the Supreme Court has explained that “the choice among
. . . reasonable alternatives remains with . . . governmental
officials.” Sitz, 496 U.S. at 453-54. It is therefore inappropri-
ate to commit to the courts—much less to the authors of a
training manual—the “decision as to which among reasonable
alternative law enforcement techniques should be employed.”
Id. at 453.

   Appellants also offered the declaration of Jack Smith, a
use-of-force expert, in connection with a motion inviting the
district court to reconsider its denial of the motions to sup-
press. Smith stated that “the record of using [controlled tire
deflation devices] is replete with death and/or serious injury
to citizens as well as law enforcement officers,” and that
“many” law enforcement agencies permit the use of such
devices exclusively as a last-resort. These statements, how-
ever, were unsupported by any citation to specific facts or evi-
dence. In addition, Smith’s resume failed to disclose any basis
in experience or expertise for his opinion that the use of
spikes “to seize a vehicle only suspected of smuggling illegal
narcotics and/or aliens is not reasonable.” The district court
found Smith’s declaration unconvincing. Particularly given
our limited role in reviewing the district court’s findings of
               UNITED STATES v. GUZMAN-PADILLA               9459
fact, we agree that the Smith declaration does not materially
affect the assessment of whether deployment of the CTDD
was safe in this instance.

                        C.   Balancing

   [17] In light of the apparent safety of deploying the tire
deflation device and the lesser degree of intrusiveness associ-
ated with the use of force against vehicles rather than persons,
we conclude that the government’s strong interests in protect-
ing the nation’s territorial integrity and interdicting the flow
of drugs alone tip the Fourth Amendment balance in the gov-
ernment’s favor. There is, however, an additional and criti-
cally important reason why the government must prevail in
this case. Battaglini “defends his actions by pointing to the
paramount governmental interest in ensuring public safety,
and [Appellants] nowhere suggest[ ] this was not the purpose
motivating” Battaglini’s decision to deploy the spike strip.
Scott, 550 U.S. at 383. Thus, “in judging whether [Bat-
taglini’s] actions were reasonable, we must consider the risk
of bodily harm that [his] actions posed to [Appellants] in light
of the threat to the public that [Battaglini] was trying to elimi-
nate.” Id. As our analysis indicates, the extreme danger posed
by the reactive conduct of smugglers confronted with a show
of authority tips the Fourth Amendment balance even more
sharply in the government’s favor.

   Appellants argue that principles underlying the knock-and-
announce rule should be applied to the use of tire deflation
devices to effect vehicle stops, and that such principles render
the conduct at issue here unreasonable per se. The Supreme
Court has articulated the principal virtues of the knock-and-
announce rule as follows:

    One of th[e] interests is the protection of human life
    and limb, because an unannounced entry may pro-
    voke violence in supposed self-defense by the sur-
    prised resident. Another interest is the protection of
9460             UNITED STATES v. GUZMAN-PADILLA
      property. . . . The knock-and-announce rule gives
      individuals the opportunity to comply with the law
      and to avoid the destruction of property occasioned
      by a forcible entry. And thirdly, the knock-and-
      announce rule protects those elements of privacy and
      dignity that can be destroyed by a sudden entrance.
      It gives residents the opportunity to prepare them-
      selves for the entry of the police.

Hudson, 547 U.S. at 594 (citations and quotation marks omit-
ted). While these animating concerns are not inapplicable in
the context of vehicle stops, see supra, slip op. at 9456, we
previously have declined an identical invitation to superim-
pose the knock-and-announce framework on the already com-
plicated jurisprudence of vehicle searches and seizures.
United States v. Garcia-Hernandez, 284 F.3d 1135, 1140 (9th
Cir. 2002) (rejecting knock-and-announce challenge to use of
a CTDD by the Border Patrol). Faced for a second time with
a situation in which Border Patrol agents had compelling rea-
sons not to activate their lights and sirens before deploying a
CTDD, we decline the invitation once again and hold that the
use of the CTDD was reasonable.7

                 IV.    BRADY DISCLOSURES

   Appellant Guzman argues that the district court’s refusal to
compel the government to produce the Border Patrol’s written
policy on the use of CTDDs violated his due process rights.
A failure to disclose material exculpatory evidence constitutes
a violation of due process under Brady. See United States v.
Bagley, 473 U.S. 667, 674 (1985). Evidence is material if
there is a reasonable probability that its disclosure would have
affected the outcome of the proceedings. Id. at 674-75.
  7
    In light of our conclusion that the seizure was reasonable, “[w]e . . .
have no occasion to consider whether exclusion of the evidence would
have been an appropriate remedy.” Alverez-Tejeda, 491 F.3d at 1018 n.3
(citing Hudson, 547 U.S. at 602).
               UNITED STATES v. GUZMAN-PADILLA               9461
“[M]ere speculation about materials in the government’s files
[does not require] the district court . . . under Brady to make
the materials available for [appellant’s] inspection.” United
States v. Michaels, 796 F.2d 1112, 1116 (9th Cir. 1986).
Rather, “unless [a] defendant is able to raise at least a color-
able claim that the [withheld material] contained evidence
favorable to [him] and material to his claim[,] . . . no constitu-
tional error . . . will have been established.” United States v.
Griffin, 659 F.2d 932, 939 (9th Cir. 1981).

   Brady claims are reviewed de novo if they are raised in the
district court. United States v. Holler, 411 F.3d 1061, 1066
(9th Cir. 2005). If they are not raised below, Brady claims are
reviewed only to determine if their denial would constitute
plain error affecting the appellant’s substantial rights. See
Fed. R. Crim. P. 52(b). Guzman’s Brady claim fails under
either standard. First, the claim is speculative. Guzman
requested the written policy in response to Battaglini’s testi-
mony that the Border Patrol deploys CTDDs only in the three
instances noted above. When asked whether these guidelines
were contained in any written policy, Battaglini replied that
there was such a policy but that he was uncertain as to
whether it contained the guidelines. Regardless, Battaglini
testified consistently that the Border Patrol adheres to the
recited standard. Indeed, the record reflects that Battaglini’s
supervisor questioned him as to whether deployment was war-
ranted under that standard. Guzman has failed to identify any
basis in the record for his suggestion that Battaglini’s actions
were inconsistent with a written policy.

  [18] Second, even if Battaglini’s actions were inconsistent
with Border Patrol policy, the policy would not have been
material to the district court’s determination. While Guzman
asserted vaguely that the Border Patrol’s failure to follow its
own regulations would “say[ ] something about what hap-
pened here,” this theory of materiality is foreclosed by our
case law. It is well-settled that the scope of the Fourth
Amendment’s protections is not to be measured by reference
9462           UNITED STATES v. GUZMAN-PADILLA
to agency guidelines and other extra-constitutional matter.
See, e.g., Virginia v. Moore, 128 S.Ct. 1598, 1603, 1607
(2008) (noting that founding-era citizens likely “were skepti-
cal of using the rules for search and seizure set by government
actors as the index of reasonableness,” and refusing to find
arrest based on probable cause unreasonable, even if state law
did prohibit arrest for offense at issue); Whren v. United
States, 517 U.S. 806, 815 (1996) (noting that “police enforce-
ment practices . . . vary from place to place and from time to
time,” and that the scope of the Fourth Amendment cannot
“be made to turn up such trivialities”). Specifically, the gov-
ernment’s violation of its own rules does not provide a basis
for the suppression of evidence in a criminal action. See, e.g.,
United States v. Hinton, 222 F.3d 664, 674 (9th Cir. 2000)
(“[S]uppresion is not the appropriate remedy for failure to fol-
low agency regulations.”); United States v. Ani, 138 F.3d 390,
392 (9th Cir. 1998) (“[V]iolation of an agency regulation does
not require suppression of evidence.”); United States v.
Choate, 619 F.2d 21, 23 (9th Cir. 1980) (“[One] may not in
a criminal prosecution seek judicial enforcement of [an]
agency regulation by means of the exclusionary rule.”). Guz-
man thus had no entitlement to the Border Patrol policy under
Brady.

                       CONCLUSION

   The stop of Appellants’ vehicle was a valid seizure incident
to a border search, and it was conducted in a reasonable, non-
excessive manner. Guzman’s Brady rights were not violated.
Accordingly, the judgment of the district court is

  AFFIRMED.
