                    FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                 
                Plaintiff-Appellee,              No. 03-10691
               v.
                                                   D.C. No.
                                                CR-03-00177-CKJ
JUAN ANTONIO VELA-ROBLES, aka
Antonio Juan Vela, Sr.,                            OPINION
             Defendant-Appellant.
                                          
        Appeal from the United States District Court
                 for the District of Arizona
        Cindy K. Jorgenson, District Judge, Presiding

                 Submitted December 7, 2004*
                   San Francisco, California

                      Filed February 7, 2005

    Before: Dorothy W. Nelson, Andrew J. Kleinfeld, and
             Ronald M. Gould, Circuit Judges.

                     Opinion by Judge Gould




  *This panel unanimously finds this case suitable for decision without
oral argument. See Fed. R. App. P. 34(a)(2).

                                1577
                 UNITED STATES v. VELA-ROBLES                1579


                          COUNSEL

Peter A. Matiatos, Tucson, Arizona, for the appellant.

Paul K. Charlton, United States Attorney, District of Arizona,
Christina M. Cabanillas, Deputy Appellate Chief, and Nathan
D. Leonardo, Assistant United States Attorney, Tucson, Ari-
zona, for the appellee.


                           OPINION

GOULD, Circuit Judge:

   Juan Antonio Vela-Robles appeals his conviction for illegal
reentry after deportation, in violation of 8 U.S.C. § 1326.
Vela-Robles contends that the district court erred in denying,
for lack of a factual basis, his requested jury instruction on the
need for freedom from official restraint to support a finding
1580                UNITED STATES v. VELA-ROBLES
of illegal reentry. We have jurisdiction under 28 U.S.C.
§ 1291, and we affirm.

                                      I

   On December 30, 2002, United States Border Patrol Agent
Chris Ofeciar received a message from a seismic sensor
located within Jackson Canyon, Arizona (about ten to fifteen
feet north of the Mexican border) that the sensor had been
activated. Ofeciar was not sure what had triggered the sensor
because seismic sensors respond to the movement of animals,
people, or vehicles, or even may be set off by the weather.

   Agents Ofeciar and Rene Ortiz responded to the sensor,
arriving in the Jackson Canyon area an estimated ten minutes
after being notified. Shortly thereafter, Ofeciar and Ortiz
encountered Vela-Robles about three-quarters to one mile
north of the border.

   Vela-Robles admitted that he was born in Mexico, that he
was not legally within the United States, and that he had been
deported in 1999, but had crossed back into the United States
through a hole in the international boundary fence. Vela-
Robles was later indicted on one count of illegal reentry after
deportation, in violation of 8 U.S.C. § 1326.

   During trial, Vela-Robles requested a jury instruction
regarding “official restraint,” to support a theory of the case
that he had not “entered” the United States.1 The government
   1
     Vela-Robles contended at trial that he was not guilty of illegal reentry,
but rather that he was guilty of attempted illegal reentry because he was
under constant governmental observation. He requested the following jury
instruction:
    Physical presence on United States soil is not enough to prove
    that an alien entered or was found in the United States. Enter or
    found in means more than the mere act of crossing the border
    line. Before an alien can be said to have entered or be found in
                   UNITED STATES v. VELA-ROBLES                      1581
objected to the instruction on grounds that it was unsupported
by the evidence and that it would unnecessarily confuse the
jury. The district court denied the requested instruction,
observing that there was no case law holding that sensor acti-
vation constituted observation, and that the instruction was
not supported by the facts. The jury gave its verdict finding
Vela-Robles guilty of one count of illegal reentry and the dis-
trict court sentenced him to forty-six months in prison. This
appeal followed, challenging the district court’s refusal to
give the requested jury instruction on “official restraint.”

                                    II

   Vela-Robles contends that the district court abused its dis-
cretion when it refused to give his proffered jury instruction
because, he argues, there was evidence that he was under offi-
cial restraint from the moment he triggered the seismic sensor
at the entrance of Jackson Canyon until his apprehension by
Agents Ofeciar and Ortiz.2

   [1] Our circuit law establishes the rule that a person does
not commit an unlawful entry into the United States if he or
she was “under constant observation by governmental author-
ities” from the time of physical entry until the time of arrest.
United States v. Castellanos-Garcia, 270 F.3d 773, 775 (9th
Cir. 2001); see also United States v. Oscar, 496 F.2d 492,
493-94 (9th Cir. 1974) (holding that an entry has not been
accomplished until physical presence is accompanied by free-

     the United States, he or she must be free from official restraint.
     The restraint may take the form of surveillance, unbeknownst to
     the alien. In order to enter or be found in the United States the
     alien must achieve the freedom to go at large and mix with the
     population.
   2
     We review for an abuse of discretion the district court’s finding that
there is an insufficient factual foundation to support a proffered jury
instruction. United States v. Castellanos-Garcia, 270 F.3d 773, 775 (9th
Cir. 2001).
1582               UNITED STATES v. VELA-ROBLES
dom from official restraint). The rule reflects the policy of the
law criminalizing illegal entry: The law seeks to prevent from
entering those who “come to stay permanently, or for a period
of time, or to go at large and at will within the United States.”
United States v. Pacheco-Medina, 212 F.3d 1162, 1164 (9th
Cir. 2000) (quoting Ex parte Chow Chok, 161 F. 627, 630
(C.C.N.D.N.Y. 1908), aff’d, 163 F. 1021 (2d Cir. 1908)). Yet
those who are under constant governmental observation or
surveillance are “in the government’s constructive custody”
for the entire time they are present, and this “official restraint”
precludes a finding of entry. United States v. Aguilar, 883
F.2d 662, 683 (9th Cir. 1989), superseded by 8 U.S.C. § 1324
(2000 & Supp. I 2004) (“The [official restraint] doctrine is
premised on the theory that the alien is in the government’s
constructive custody at the time of physical entry. By con-
trast, when an alien is able to exercise his free will subsequent
to physical entry, he is not under official restraint.”); see also
Castellanos-Garcia, 270 F.3d at 775 (holding that if a person
is “under constant observation or surveillance from the
moment of his entry to the time of his capture, he is not free
from official restraint”); Pacheco-Medina, 212 F.3d at 1163-
64 (holding that “physical presence is not enough” to consti-
tute an entry; the person must at some time while present also
be free from official restraint).3

  Vela-Robles argues that he was under constant surveillance
because Jackson Canyon is a natural gorge and there are only
two practical ways out: the entrance at the U.S.-Mexican bor-
der where Vela-Robles crossed over, and the exit about one
mile north of the border. Vela-Robles suggests that once he
  3
    Other circuits have established a similar doctrine. See, e.g., Nyirenda
v. INS, 279 F.3d 620, 623-25 (8th Cir. 2002); Farquharson v. U.S. Attor-
ney General, 246 F.3d 1317, 1321-22 (11th Cir. 2001); Correa v. Thorn-
burgh, 901 F.2d 1166, 1171-72 (2d Cir. 1990) (“ ‘Freedom from official
restraint’ means that the alien who is attempting entry is no longer under
constraint emanating from the government that would otherwise prevent
her from physically passing on.”). None of the federal circuits have
adopted a contrary rule.
                 UNITED STATES v. VELA-ROBLES               1583
triggered the seismic sensor, he was under constant observa-
tion or surveillance because Border Patrol agents knew he
was in the canyon. The issue that we must decide is whether
Vela-Robles was under official restraint within the meaning
of our case law, so as to prohibit a conclusion that he had
unlawfully entered the United States. This turns on whether
a person who triggers a seismic sensor, at least in the circum-
stances presented, may be considered by law to be under
constant observation or surveillance.

   [2] We see little in reason or analysis that could support the
argument urged by Vela-Robles. Detection by a seismic sen-
sor does not amount to observation or surveillance for the pur-
pose of showing official restraint; in light of the rule’s
purpose, an alien must be “in the visual or physical grasp of
the authorities at all times” to show that he or she is under
official restraint. See Pacheco-Medina, 212 F.3d at 1165. It
would not be appropriate to extend the doctrine to encompass
a case such as this, involving the mere triggering of seismic
sensors, absent constant visual observation. Vela-Robles was
not subject to official restraint before his arrest because he
was not in the constant visual or physical grasp of govern-
mental authorities after he crossed the border. Vela-Robles
undisputedly traveled at least a half of a mile north of the bor-
der before Agents Ofeciar and Ortiz detected his presence.
See Castellanos-Garcia, 270 F.3d at 774-76 (holding that the
evidence did not support an “official restraint” theory where
no agent saw the defendant cross the border, and the defen-
dant was found 100 yards north of the U.S.-Mexican border).
Because the reasons for the rule that official restraint pre-
cludes a conclusion of illegal entry, despite physical presence,
are not applicable, we decline to extend the scope of the rule
to cover a person who has merely tripped a seismic sensor and
who may have difficulty escaping.

                              III

  [3] A district court is not required to give an instruction on
a defendant’s official restraint theory when there is no evi-
1584             UNITED STATES v. VELA-ROBLES
dence to support the theory. Id. at 777. We hold that the dis-
trict court did not abuse its discretion in determining that there
was an insufficient factual basis for Vela-Robles’s requested
instruction because Vela-Robles presented no evidence show-
ing that he was under constant observation or surveillance by
government officials from the moment he crossed the border
until he was apprehended.

  AFFIRMED.
