                 FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                No. 04-10648
                Plaintiff-Appellee,         D.C. No.
               v.                        CR-04-00216-
STUART ROMM,                               PMP(PAL)
             Defendant-Appellant.
                                          OPINION

       Appeal from the United States District Court
                for the District of Nevada
         Philip M. Pro, District Judge, Presiding

                 Argued and Submitted
       December 5, 2005—San Francisco, California

                    Filed July 24, 2006

    Before: Betty B. Fletcher, David R. Thompson, and
              Carlos T. Bea, Circuit Judges.

                   Opinion by Judge Bea




                           8261
                   UNITED STATES v. ROMM                 8265


                         COUNSEL

Jason F. Carr, Las Vegas, Nevada, for appellant Stuart Romm.

Nancy J. Koppe (briefed) and Daniel R. Schiess (argued), Las
Vegas, Nevada, for appellee United States of America.


                         OPINION

BEA, Circuit Judge:

   We are called upon to decide whether, absent a search war-
rant or probable cause, the contents of a laptop computer may
be searched at an international border and, if so, what evi-
dence is sufficient to convict its owner of receiving and pos-
sessing child pornography. We also address an error in the
jury instructions on the mental state required for knowingly
possessing child pornography.

  Defendant Stuart Romm connected to the internet from a
Las Vegas hotel room and visited websites containing images
8266                    UNITED STATES v. ROMM
of child pornography. As Romm viewed the images online
and enlarged them on his screen, his computer automatically
saved copies of the images to his “internet cache.”1 Based on
40 images deleted from his internet cache and two images
deleted from another part of his hard drive,2 Romm was con-
victed of knowingly receiving and knowingly possessing
child pornography in violation of 18 U.S.C. §§ 2252A(a)(2),
(a)(5)(B). Romm appeals both of these convictions, as well as
his concurrent mandatory minimum sentences of ten and fif-
teen years.

   First, Romm claims the evidence of his crime should have
been suppressed as the fruits of an unlawful border search.
Second, he challenges the sufficiency of the evidence support-
ing each of his convictions, arguing he cannot be found guilty
of possessing or receiving child pornography, when he merely
viewed child pornography without “downloading”3 any of it
   1
     The “internet cache” or “internet temporary folder” is a “set of files
kept by a web browser to avoid having to download the same material
repeatedly. Most web browsers keep copies of all the web pages that you
view, up to a certain limit, so that the same images can be redisplayed
quickly when you go back to them.” DOUGLAS DOWNING, ET AL., DICTIONARY
OF COMPUTER AND INTERNET TERMS, 149 (Barron’s 8th Ed. 2003). According
to expert testimony at trial, the cache is a set of files on the user’s hard
drive.
   2
     Specifically, two images of child pornography had been deleted from
Romm’s “recycle bin.” The “recycle bin” is an area of the hard drive
where Windows stores files that the user deletes. While the user does not
necessarily have to delete a file manually for it go into the recycle bin,
removal of files from the recycle bin generally requires manual steps to be
taken by the user. Since Romm was indicted of possessing three or more
images of child pornography, however, the two images in his recycle bin
are insufficient to support his conviction. Therefore, we will not consider
them here.
   3
     The term “downloading” generally refers to the act of manually storing
a copy of an image on the hard drive for later retrieval. The internet cache,
by contrast, is an area to which the internet browser automatically stores
data to speed up future visits to the same websites. See United States v.
Parish, 308 F.3d 1025, 1030-31 (9th Cir. 2002) (contrasting downloading
and caching of files); see also United States v. Mohrbacher, 182 F.3d
1041, 1045-48 (9th Cir. 1999) (describing downloading).
                        UNITED STATES v. ROMM                         8267
to his hard drive. Third, he claims the refusal of his proffered
jury instruction on the statutory definition of a “visual depic-
tion” deprived him of the right to present a defense. Fourth,
he argues that the omission of an element from the jury
instructions on “knowing possession” and the district court’s
refusal to supplement the instructions in response to a note
from the jury together constitute reversible plain error. Fifth,
he challenges the enhancement of his sentences based on prior
convictions for predicate offenses.

   We have jurisdiction pursuant to 28 U.S.C. § 1291, and for
the reasons stated herein, affirm Romm’s convictions, but
vacate his sentences and remand to the district court for resen-
tencing.

                          BACKGROUND

   From January 23, 2004 to February 1, 2004, Romm
attended a training seminar held by his new employer in Las
Vegas, Nevada. When the training seminar ended on February
1, 2004, Romm flew from Las Vegas, Nevada to Kelowna,
British Columbia on business.

   At the British Columbia airport, Canada’s Border Services
Agency discovered that Romm had a criminal history and
stopped him for questioning. Romm admitted he had a crimi-
nal record4 and was currently on probation. Agent Keith
Brown then asked Romm to turn on his laptop and briefly
examined it. When Brown saw several child pornography
websites in Romm’s “internet history,”5 Brown asked Romm
if he had violated the terms of his probation by visiting these
  4
     In an unrelated Florida state court prosecution, Romm pleaded nolo
contendere to two counts of promoting sexual performance by a child and
one count of child exploitation by means of a computer.
   5
     As one expert testified at trial, the internet history is a “documented
history of your travels on the Internet. You could actually go back through
your Internet history and see where you’ve been on the Internet.”
8268                UNITED STATES v. ROMM
websites. Romm answered “Yes,” and also said, “That’s it.
My life’s over.”

   Meanwhile, Canada’s immigration service had decided not
to admit Romm into the country. Romm withdrew his applica-
tion for entry and was placed under detention until the next
flight to Seattle. Agent Brown then informed U.S. Customs in
Seattle that Romm had been denied entry and possibly had
illegal images on his computer.

   On February 2, 2004, Romm returned to Seattle. At the
Seattle-Tacoma airport, Romm was interviewed by Agents
Macho and Swenson of Immigration and Customs Enforce-
ment (“ICE”).6 The agents told Romm they needed to search
his laptop for illegal images, and could arrange for the exami-
nation to be completed that night. Romm agreed. He told the
agents he had been in sole possession of the laptop for the
previous six to eight weeks. He also told the agents he had
“drifted” away from his “therapy,” and experienced “occa-
sional lapses” during which he would view child pornogra-
phy. But Romm repeatedly denied having any child
pornography on his laptop.

   ICE conducted a preliminary forensic analysis of the hard
drive in Romm’s laptop. When the preliminary analysis
revealed ten images of child pornography, Agent Macho con-
fronted Romm with this information and asked Romm why he
had lied about having images on his computer. Romm looked
down, adopted a “confessional mode,” made little eye contact
with his interrogators, and said that “he knew [the agents]
were gonna find something on the computer.” He also stated
the agents had every right to arrest him and would probably
do so.
  6
   Agents Macho and Swenson administered a Miranda warning, the
validity of which Romm does not challenge on appeal.
                        UNITED STATES v. ROMM                           8269
   Romm then described to the agents how he used Google7
to search for child pornography websites. When he found pic-
tures he liked, Romm would keep them on his screen for five
minutes and then delete them. Romm used the terms “save”
and “download” to describe this operation. While staying in
his hotel room in Las Vegas, Romm viewed child pornogra-
phy and masturbated twice, while or shortly after viewing the
child pornography; he claimed to have then deleted such
images. In all, Romm used the internet for approximately six-
and-a-half hours during his week-long stay in Las Vegas.

                 Results of the Forensic Analysis

   At trial, the government called three witnesses to testify
about the forensic analysis of the hard drive in Romm’s lap-
top. First, Agent Camille Sugrue described the preliminary
analysis that she conducted with software called “EnCase.”
With EnCase, it is possible to recover deleted files,8 as well
as information showing when the files were created, accessed,
or modified. In conducting the preliminary analysis, Sugrue
found ten images of child pornography. All of the images she
found had been deleted from Romm’s hard drive.

   Second, Detective Timothy Luckie testified to the results of
the full forensic analysis of Romm’s hard drive. Luckie con-
firmed that all of the child pornography on Romm’s computer
had been deleted. The vast majority of the images Luckie
found had been deleted from Romm’s internet cache. EnCase
did not reveal when the files had been deleted. Luckie’s anal-
ysis also showed that Romm had enlarged a few smaller “thumb-
nail”9 images in the internet cache.
  7
     Google is a search engine used to find information on the Internet.
  8
     A file is “a block of information stored on disk, tape, or similar media.
A file may contain a program, document, or a collection of data (such as
a mailing list).” DOWNING, supra at 188.
   9
     The term “thumbnail,” which derives from an artist’s thumbnail sketch,
refers to “a small image of a graphics file displayed in order to help you
identify it.” DOWNING, supra at 495.
8270                UNITED STATES v. ROMM
   Luckie next explained how files in the internet cache are
deleted. First, on the default setting, the web browser auto-
matically empties the internet cache when it reaches a given
size. Second, the user can instruct the browser to empty the
internet cache. Third, users who know where the internet
cache is located can go into the cache and manually delete the
files, rather than effect the deletions automatically through the
web browser’s default setting. EnCase did not reveal the set-
tings on Romm’s web browser, or how his internet cache had
been emptied. Luckie opined “through experience and train-
ing,” however, that Romm either had instructed his browser
to empty the cache or had deleted the files manually. Luckie
also noted Romm had erased his internet history at 2:25 p.m.
on February 2, 2004, the same afternoon that Canada’s Border
Services Agency placed Romm on a flight back to Seattle.

   Finally, Luckie testified that files in the internet cache are
accessible, albeit “system-protected.” A user who knows how
to find the internet cache can view the images stored there.
Once the user views the image, the user “can print, rename,
[or] save [it] elsewhere, the same thing you can do with any
other file.”

   The government’s third expert witness, Darryl Cosme,
exhibited to the jury 42 images of child pornography recov-
ered from Romm’s hard drive. He told the jury the prove-
nance of some images, when each image was saved to the
cache, and whether that image was a thumbnail or a full-sized
picture. Cosme identified several websites in the internet his-
tory as related to child pornography.

   Romm’s expert witness, Thomas Keller, testified how the
internet cache is “system-protected.” According to Keller,
“system-protection” blocks any user from accessing the
cache, except by means of “system-commands.” If, however,
the user executes a system-command notwithstanding the
computer’s warning, he can copy the cached image to another
location on the hard drive or view the image by copying it
                       UNITED STATES v. ROMM                8271
into an open program. Keller also testified that people delete
their internet history and internet cache for legitimate reasons.
Finally, Keller testified he found no evidence Romm ever
went into the internet cache, or accessed the files there.

   Before trial, Romm moved to suppress the evidence
obtained through the border search of his laptop and moved
to force the government to elect between multiplicitous
counts. The court orally denied both motions. After a four-day
trial, the jury deliberated for six hours and found Romm
guilty of both possessing and receiving child pornography. At
sentencing, the court found Romm had committed a predicate
offense under 18 U.S.C. § 2252A(b), and accordingly
imposed concurrent mandatory minimum sentences of ten and
fifteen years. Romm then filed a timely notice of appeal.

                           ANALYSIS

                  I.     BORDER SEARCH

   [1] First, we address whether the forensic analysis of
Romm’s laptop falls under the border search exception to the
warrant requirement. We review the legality of a border
search de novo. United States v. Okafor, 285 F.3d 842, 845
(9th Cir. 2002). Under the border search exception, the gov-
ernment may conduct routine searches of persons entering the
United States without probable cause, reasonable suspicion,
or a warrant. See United States v. Montoya de Hernandez, 473
U.S. 531, 538 (1985). For Fourth Amendment purposes, an
international airport terminal is the “functional equivalent” of
a border. See Okafor, 285 F.3d at 845 (citing Almeida-
Sanchez v. United States, 413 U.S. 266, 272-73 (1973)). Thus,
passengers deplaning from an international flight are subject
to routine border searches.

  [2] Romm argues he was not subject to a warrantless border
search because he never legally crossed the U.S.-Canada bor-
der. We have held the government must be reasonably certain
8272                   UNITED STATES v. ROMM
that the object of a border search has crossed the border to
conduct a valid border search. See United States v. Corral-
Villavicencio, 753 F.2d 785, 788-89 (9th Cir. 1985); United
States v. Tilton, 534 F.2d 1363, 1366-67 (9th Cir. 1976);
United States v. Garcia, 415 F.2d 1141, 1144 (9th Cir. 1969).
In all these cases, however, the issue was whether the person
searched had physically crossed the border. There is no
authority for the proposition that a person who fails to obtain
legal entry at his destination may freely reenter the United
States; to the contrary, he or she may be searched just like any
other person crossing the border. See United States v. 1903
Obscene Magazines, 907 F.2d 1338, 1341 (2d. Cir. 1990)
(seizure of a shipment of magazines rejected by Canada
“clearly permissible” as a border search); People v. DeLoach,
297 N.Y.S.2d 220, 222-23 (1969) (travelers denied entry by
Canada for refusal to pay a duty properly searched without a
warrant); see also United States v. Adams, 1 F.3d 1566, 1577-
78 (11th Cir. 1993); United States v. Stanley, 545 F.2d 661,
666 (9th Cir. 1976).

   [3] Nor will we carve out an “official restraint”10 exception
to the border search doctrine, as Romm advocates. We
assume for the sake of argument that a person who, like
Romm, is detained abroad has no opportunity to obtain for-
eign contraband. Even so, the border search doctrine is not
limited to those cases where the searching officers have rea-
son to suspect the entrant may be carrying foreign contraband.
Instead, “ ‘searches made at the border . . . are reasonable
simply by virtue of the fact that they occur at the border.’ ”
United States v. Flores-Montano, 541 U.S. 149, 152-53
(2004) (quoting United States v. Ramsey, 431 U.S. 606, 616
(1977)). Thus, the routine border search of Romm’s laptop
was reasonable, regardless whether Romm obtained foreign
contraband in Canada or was under “official restraint.”
  10
    Under our cases construing 8 U.S.C. § 1326, the act of “being found”
in the United States requires the alien to be present in the United States
while free from “official restraint.” See, e.g., United States v. Pacheco-
Medina, 212 F.3d 1162, 1165 (9th Cir. 2000).
                        UNITED STATES v. ROMM                         8273
  [4] Finally, and for the first time in his reply brief, Romm
argues the search of his laptop was too intrusive on his First
Amendment interests to qualify as a “routine” border search.
See generally Okafor, 285 F.3d at 846 (noting the difference
between routine and non-routine searches). We decline to
consider this issue here because “arguments not raised by a
party in its opening brief are deemed waived.” See Smith v.
Marsh, 194 F.3d 1045, 1052 (9th Cir. 1999). Therefore, eval-
uating the border search of Romm’s laptop solely as a routine
search, we hold the district court correctly denied Romm’s
motion to suppress.11

         II.   SUFFICIENCY OF THE EVIDENCE

   Next, Romm challenges the sufficiency of the evidence that
he committed the acts of “possessing” and “receiving” child
pornography. The sufficiency of the evidence is reviewed de
novo. See United States v. Shipsey, 363 F.3d 962, 971 n.8 (9th
Cir. 2004). “There is sufficient evidence to support a convic-
tion if, ‘viewing the evidence in the light most favorable to
the prosecution, any rational trier of fact could have found the
essential elements of the crime beyond a reasonable doubt.’ ”
Id. (quoting Jackson v. Virginia, 443 U.S. 307, 319 (1979)).
Romm concedes there was sufficient evidence for the jury to
find he acted with the requisite mental state of “knowingly,”
   11
      The Supreme Court’s recent decision in Flores-Montano, 541 U.S. at
152-53, suggests that the search of a traveler’s property at the border will
always be deemed “routine,” absent a showing the search technique risks
damage to the searched property. Since Flores-Montano two circuits have
addressed the search of computers at the border. See United States v.
Irving, 432 F.3d 401, 413-14 (2d Cir. 2005) (affirming border search of
floppy diskettes based on reasonable suspicion that they contained child
pornography and, therefore, not deciding whether the search was routine
or non-routine); Cf. United States v. Ickes, 393 F.3d 501, 505-07 (4th Cir.
2005) (Wilkinson, J.) (affirming border search of a laptop computer and
suggesting that it was categorically reasonable as a routine border search).
Since this issue is not before us here, however, we need not decide
whether the search of Romm’s laptop was “non-routine,” and if so,
whether it was supported by reasonable suspicion.
8274                UNITED STATES v. ROMM
but rather contends that the act he committed was merely the
viewing of child pornography, not the possession or receipt of
it. We disagree. In the electronic context, a person can receive
and possess child pornography without downloading it, if he
or she seeks it out and exercises dominion and control over
it. See United States v. Tucker, 305 F.3d 1193, 1204 (10th Cir.
2002), cert. denied, 537 U.S. 1223 (2003) (“Tucker II”). Here,
we hold Romm exercised dominion and control over the
images in his cache by enlarging them on his screen, and sav-
ing them there for five minutes before deleting them. While
the images were displayed on Romm’s screen and simulta-
neously stored to his laptop’s hard drive, he had the ability to
copy, print, or email the images to others. Thus, this evidence
of control was sufficient for the jury to find that Romm pos-
sessed and received the images in his cache.

             Possession of Child Pornography

   [5] As we explain below, whether Romm “received” the
images in his cache depends on whether he knowingly took
possession of them. Thus, we begin by analyzing his convic-
tion for knowingly possessing child pornography. It is a fed-
eral crime to “knowingly possess[ ] any book, magazine,
periodical, film, videotape, computer disk, or any other mate-
rial that contains an image of child pornography. . . .” 18
U.S.C. § 2252A(a)(5)(B). “Child pornography” is defined as
a “visual depiction,” id. § 2256(8), and the term “visual depic-
tion” “includes undeveloped film and videotape, and data
stored on computer disk or by electronic means which is
capable of conversion into a visual image.” Id. § 2256(5)
(emphasis added).

   Romm’s first argument is that files in the internet cache are
not “visual depictions” and, therefore, lie beyond the reach of
18 U.S.C. § 2252A. Specifically, Romm argues the files in the
cache are not “data . . . which is capable of conversion into
a visual image,” because they must be copied to another loca-
tion on the disk before they are fully accessible. As Romm’s
                    UNITED STATES v. ROMM                    8275
expert witness, Thomas Keller, testified, the cache is a
“system-protected” area, which the operating system tries to
prevent users from accessing by displaying a warning that
access involves an “unsafe” system-command. The user can,
however, override the warning, and open and view the cached
files, by executing a system-command. The following testi-
mony by Keller is pertinent here:

    Q — What would a user of Windows XP Pro have
    to do to view [the cached] image if off line?

    A — If he’s off line, . . . , you have to physically
    move that image to another file folder. You could
    either drag it to another one, copy it and paste it to
    an open window [or] to [ ] some kind of [ ] software
    that would allow you to see images or cut it and
    paste it to another folder.

Keller further explained the user could perform the above
operation by right-clicking his mouse and choosing from
among a limited set of system-commands. Thus, the user can
access the files in the cache, and once he accesses them, the
user can, according to the government’s expert, “print,
rename, [or] save [the files] elsewhere, the same thing you
can do with any other file.”

   [6] In essence, Romm’s argument is that the cached files do
not become “visual depictions” until the user takes the addi-
tional step of converting them into ordinary files. The statute,
however, speaks of data files that are capable of conversion
into a viewable form, not data files that are immediately view-
able without any further affirmative steps. See 18 U.S.C.
§ 2256(5). Here, Romm could convert the image files in his
internet cache into a viewable form by right-clicking his
mouse. Also, when Romm had the images displayed on his
screen that were contemporaneously stored to the cache, he
could copy, print, or email them to another person, just as
with ordinary files. Therefore, we hold there was sufficient
8276                   UNITED STATES v. ROMM
evidence from which the jury could find that the images
stored in Romm’s internet cache were “visual depictions.”12

   [7] Second, Romm challenges the sufficiency of evidence
of his control over the images in the internet cache. We begin
with the text of 18 U.S.C. § 2252A. We interpret the term
“knowing possession” according to its plain meaning, and
presume Congress intended to apply traditional concepts of
possession. See United States v. Mohrbacher, 182 F.3d 1041,
1048-49 (9th Cir. 1999); Tucker II, 305 F.3d at 1204. “Posses-
sion” is “[t]he fact of having or holding property in one’s
power; the exercise of dominion over property.” BLACK’S LAW
DICTIONARY 1183 (7th Ed. 1999). Thus, to establish posses-
sion, “ ‘[t]he government must prove a sufficient connection
between the defendant and the contraband to support the
inference that the defendant exercised dominion and control
over [it].’ ” United States v. Carrasco, 257 F.3d 1045, 1049
(9th Cir. 2001) (quoting United States v. Gutierrez, 995 F.2d
169, 171 (9th Cir. 1993) (internal quotation marks and alter-
ations omitted)).

  In Mohrbacher, 182 F.3d at 1048-1051, we held that a
defendant who downloaded child pornography could be pros-
ecuted for receiving child pornography, but not for transport-
ing it. Our reasoning in Mohrbacher also clearly implied that
a defendant who downloads child pornography can be prose-
   12
      This holding is supported by United States v. Smith, 795 F.2d 841,
846-47 (9th Cir. 1986), where we held that undeveloped film is a “visual
depiction,” even though the pictures must first undergo chemical process-
ing before they can be viewed. Smith construed one of the statute’s precur-
sors, which left the term “visual depiction” undefined and did not
expressly list undeveloped film as an example of a visual depiction. See
id., 795 F.2d at 846 n.3; cf. 18 U.S.C. § 2256(5). Therefore, Smith sup-
ports our interpretation of the term “visual depiction” to include Romm’s
cache files, even if further affirmative steps are required to convert them
into a viewable form. See Smith, 795 F.2d at 846-47; see also United
States v. Hockings, 129 F.3d 1069, 1071-72 (9th Cir. 1997) (relying on
Smith to hold that compressed image files (“GIF’s”) are visual depictions).
                    UNITED STATES v. ROMM                   8277
cuted for knowing possession of child pornography. See id. at
1048. Recently, in United States v. Gourde, 440 F.3d 1065,
1070-73 (9th Cir. 2006) (en banc), we addressed the evidence
necessary to uphold a search warrant for child pornography
located on a defendant’s computer. There, we found the
search warrant valid based on the defendant’s continued, pay-
ing membership in a child pornography website, and the like-
lihood that “[illegal] images were almost certainly retrievable
from his computer if he had ever received or downloaded
them.” Id. at 1071. Even though the affidavit supporting the
warrant did not attest that the defendant had downloaded any
files, it nonetheless provided the requisite “ ‘fair probability’
Gourde had, in fact, received or downloaded images.” Id. (cit-
ing Illinois v. Gates, 462 U.S. 213, 240 (1983)). Neither
Gourde nor Mohrbacher, however, answers the question
before us today: whether a defendant may be convicted of
possessing and receiving images of child pornography found
in the internet cache.

   [8] Of our sister circuits, only the Tenth Circuit has
addressed whether a defendant can be convicted of possessing
child pornography accessed from the internet and contempo-
raneously stored to the internet cache. See Tucker II, 305 F.3d
at 1204-05. In Tucker II, the defendant was convicted of pos-
sessing thousands of images of child pornography in his inter-
net cache and deleted from his hard drive. Id. at 1198; see
also United States v. Tucker, 150 F.Supp.2d 1263, 1265-66
(D. Utah 2001) (“Tucker I”), aff’d by Tucker II, 305 F.3d at
1204-05. In Tucker, the defendant also saved one image to his
hard drive, and had either copied or attempted to copy a set
of images to a floppy diskette. See Tucker I, 150 F.Supp.2d
at 1265-66. The Tenth Circuit held that the images in Tuck-
er’s internet cache furnished sufficient evidence to support his
conviction for possession of child pornography. See Tucker II,
305 F.3d at 1199, 1204-05. Specifically, the evidence at trial
established the defendant’s unfettered access to the internet
cache, his intent to seek the images out, and his knowledge of
his web browser’s caching function. See id. Therefore, since
8278                    UNITED STATES v. ROMM
Tucker “knew his browser cached the image files,” the Tenth
Circuit held that “each time Tucker intentionally sought out
and viewed child pornography with his Web browser he
knowingly acquired and possessed the images.” Id. at 1205.13

   [9] We agree generally with Tucker’s analysis. It is true
that the images possessed by the defendant must be “contain[-
ed]” on a “computer disk or other [tangible] material.” 18
U.S.C. § 2252A(a)(5)(B); United States v. Lacy, 119 F.3d
742, 747-48 (9th Cir. 1997). It is also true that “a defendant
may be convicted [of possessing child pornography] only
upon a showing that he knew that the [disks] contained an
unlawful visual depiction.” See id. Therefore, to possess the
images in the cache, the defendant must, at a minimum, know
that the unlawful images are stored on a disk or other tangible
material in his possession.

   However, Romm exercised control over the cached images
while they were contemporaneously saved to his cache and
displayed on his screen. At that moment, as the expert testi-
mony here established, Romm could print the images, enlarge
them, copy them, or email them to others. No doubt, images
could be saved to the cache when a defendant accidentally
views the images, as through the occurrence of a “pop-up,”14
for instance. But that is not the case here.
  13
      In United States v. Bass, 411 F.3d 1198, 1201-02 (10th Cir. 2005),
cert. denied, 126 S.Ct. 1106 (2006), a divided panel of the Tenth Circuit
upheld a conviction for possessing child pornography in the internet cache
where the defendant claimed ignorance of the browser’s caching function.
Unlike in Tucker II, where the defendant conceded his knowledge of the
caching function, see id., 305 F.3d at 1204, the defendant in Bass claimed
that a computer virus caused his browser to save child pornography with-
out his knowledge. See Bass, 411 F.3d at 1200; id. at 1207 (Kelly, J., dis-
senting). But the defendant in Bass had used specialized software to
remove the traces of child pornography from his internet history and his
registry. See id. at 1200, 1202. In Bass’s attempts to delete the child por-
nography, the Tenth Circuit found sufficient evidence of Bass’s knowl-
edge to support his conviction for knowingly possessing the images found
in the cache. Id. at 1201-02.
   14
      As an expert testified at trial, a “pop-up” is an unsolicited advertise-
ment that will appear in a window that “pops up” unwanted in the user’s
web browser.
                    UNITED STATES v. ROMM                  8279
   By his own admission to ICE, Romm repeatedly sought out
child pornography over the internet. When he found images
he “liked,” he would “view them, save them to his computer,
look at them for about five minutes [ ] and then delete them.”
Either while viewing the images or shortly thereafter, Romm
twice masturbated. He described his activities as the “saving”
and “downloading” of the images. While the images were dis-
played on screen and simultaneously stored to his cache,
Romm could print them, email them, or save them as copies
elsewhere. Romm could destroy the copy of the images that
his browser stored to his cache. And according to detective
Luckie, Romm did just that, either manually, or by instructing
his browser to do so. Forensic evidence showed that Romm
had enlarged several thumbnail images for better viewing. In
short, given the indicia that Romm exercised control over the
images in his cache, there was sufficient evidence for the jury
to find that Romm committed the act of knowing possession.

   Romm contends that the rule of lenity must caution us
against construing the terms “possession” and “receipt” in 18
U.S.C. § 2252A to encompass cached internet files. The rule
of lenity, which is rooted in considerations of notice, requires
courts to limit the reach of criminal statutes to the clear
import of their text and construe any ambiguity against the
government. See, e.g., Ladner v. United States, 358 U.S. 169,
177 (1958); McBoyle v. United States, 283 U.S. 25, 27
(1931); United States v. Napier, 861 F.2d 547, 548 (9th Cir.
1988). Here, however, the statute employs the well-known
concepts of “possession” and “receipt,” each of which
depends on the evidence of control. Thus, this is not a case
where the language of the criminal statute is ambiguous or, by
its plain meaning, too narrow to embrace the government’s
theory of prosecution.

   In a recent dissent, one of our colleagues has drawn on the
rule of lenity to opine that images saved to the cache are nei-
ther “received” nor “possessed” within the meaning of 18
U.S.C. § 2252. See Gourde, 440 F.3d at 1080-82 (Kleinfeld,
8280                UNITED STATES v. ROMM
J., dissenting). Assuming a lack of control over the images
saved to the cache, our colleague has opined that a person
who looks at child pornography over the internet no more “re-
ceives” it, than a visitor to the Louvre “receives” a visualiza-
tion of the Mona Lisa. See id. at 1082. However, as the record
here indicates, Romm had access to, and control over, the
images that were displayed on his screen and saved to his
cache. He could copy the images, print them or email them to
others, and did, in fact, enlarge several of the images. This
control clearly differentiates Romm’s conduct from that of a
visitor to the Louvre who gazes on the Mona Lisa, even if we
put aside the stringent museum rules against photographing or
copying without museum permission.

   [10] In short, we hold there was sufficient evidence for the
jury to conclude that the images in the cache were “visual
depictions” because they could be accessed and viewed by
Romm. Further, given Romm’s ability to control the images
while they were displayed on screen, and the forensic and
other evidence that he actually exercised this control over
them, there was sufficient evidence to support the jury’s find-
ing that Romm possessed three or more images of child por-
nography. Coupled with Romm’s conceded knowledge that
the images were saved to his disk, the prosecution produced
sufficient evidence to establish every element of knowingly
possessing child pornography under 18 U.S.C. § 2252A.

               Receiving Child Pornography

   [11] Since Romm knowingly possessed the files in the
internet cache, it follows that he also knowingly received
them. Federal law makes it a crime to “knowingly receiv[e]
or distribut[e] . . . any child pornography that has been
mailed, or shipped or transported in interstate or foreign com-
merce. . . .” 18 U.S.C. § 2252A(a)(2). Generally, federal stat-
utes criminalizing the receipt of contraband require a
“knowing acceptance or taking of possession” of the prohib-
ited item. See United States v. Lipps, 659 F.2d 960, 962 (9th
                       UNITED STATES v. ROMM                     8281
Cir. 1981) (per curiam) (construing 18 U.S.C. § 922(h)); see
also, e.g., United States v. Ladd, 877 F.2d 1083, 1087 (1st
Cir. 1989) (receiving counterfeit money); United States v.
Strauss, 678 F.2d 888, 893-94 (11th Cir. 1982) (receiving
stolen property). Moreover, we have applied this principle to
18 U.S.C. § 2252’s prohibitions on receiving and possessing
child pornography. See Mohrbacher, 182 F.3d at 1048 (“An
individual who . . . takes possession or accepts delivery of the
visual image; . . . has therefore certainly received it.”). Specif-
ically, in Mohrbacher, we held that downloading child por-
nography constitutes both the act of possession and receipt.
Id. Here, we have held that the files stored to the cache were
possessed by Romm, and thus, that the caching of files, on the
facts of this case, is analogous to downloading for the purpose
of possession. By analogy, it follows under Mohrbacher that
knowingly taking possession of the files in the cache also con-
stitutes the “knowing receipt” of those files. Therefore, we
hold that the evidence was sufficient to sustain Romm’s con-
viction for receiving child pornography.15

                III.   JURY INSTRUCTIONS

       A.   Refusal of Romm’s Proffered Instruction
                   on “Visual Depiction”

   Next, Romm claims the district court deprived him of the
right to present his theory of the case by refusing his proffered
jury instruction on the statutory definition of “visual depic-
tion.” If the defense theory has a basis in fact and law, the
failure to give a proffered jury instruction on that theory is per
se reversible error. See United States v. Escobar de Bright,
742 F.2d 1196, 1201 (9th Cir. 1984). However, “it is not
reversible error to reject a defendant’s proposed instruction on
  15
    We express no opinion on the possible multiplicity of the charges
brought against Romm. Romm made a pretrial motion for the prosecution
to elect between multiplicitous counts, but does not appeal its denial.
Therefore, we need not reach this issue here.
8282                UNITED STATES v. ROMM
his theory of the case if other instructions, in their entirety,
adequately cover that defense theory.” United States v.
Mason, 902 F.2d 1434, 1438 (9th Cir. 1990). We review de
novo whether the jury instructions adequately cover the
defense’s theory of the case. See United States v. Duran, 59
F.3d 938, 941 (9th Cir. 1995).

   During the jury instructions conference, Romm proposed
that the court instruct the jury on the legal definition of “vi-
sual depiction” and require the jury to find whether Romm
knowingly received “visual depictions” onto the hard drive of
his laptop computer. This instruction was necessary, Romm
argued, to cover the “storage” element of the offense. The
court refused Romm’s proffered instruction because “storage
is not an element” of the offense and because Romm had, in
any event, conceded that the cached files were “visual depic-
tions” by stipulating that the cached files were “child pornog-
raphy.” We need not address Romm’s stipulation, however,
because we hold that the instructions given adequately cov-
ered Romm’s theory of the case.

   [12] The jury was instructed that “a person has received
something if they [sic] have knowingly come into possession
of it.” The instructions defined “possession” as “know[ing] of
[an object’s] presence and ha[ving] the power and intention to
control it.” The court’s definition of “receiving,” as know-
ingly taking possession, thus required the jury to find whether
Romm had possession and control over the images in the
cache. Romm’s “visual depictions” defense was premised on
the notion that files in the cache are too inaccessible to be the
object of “possession” or “receipt” under § 2252A. In
essence, he challenged whether he had access to and control
over the images in the cache. The instructions on receiving,
by incorporating a finding of control, encompassed Romm’s
theory of the case.

B.     Instructions on the Mens Rea of Knowing Possession

  Next, Romm claims the jury instructions on the elements of
knowing possession are plainly erroneous under our decision
                       UNITED STATES v. ROMM                        8283
in Lacy, 119 F.3d at 747-50. He also challenges the district
court’s refusal to supplement those instructions in response to
a note from the jury expressing confusion over whether
Romm had to know the images were located on his disk.

   Since Romm failed to object on either ground, we review
for plain error. See, e.g., United States v. Recio, 371 F.3d
1093, 1099-1102 (9th Cir. 2004). Under this standard, we
have discretion to reverse only if there is (1) error, (2) that is
“plain”—i.e., obvious—under current law, and (3) that “affec-
t[s] [Romm’s] substantial rights.” See United States v. Olano,
507 U.S. 725, 732-34 (1993). If these three elements of plain
error are established, we will exercise our discretion to
reverse only if (4) leaving the error uncorrected would “ ‘seri-
ously affect[ ] the fairness, integrity or public reputation of
judicial proceedings.’ ” Id. at 736 (quoting United States v.
Atkinson, 297 U.S. 157, 160 (1936)).

   In Lacy, 119 F.3d at 747-50, the defendant appealed his
conviction on one count of knowingly possessing “3 or more
matters” that contained visual depictions of child pornogra-
phy. The defendant there had downloaded several pictures of
child pornography. He claimed, however, not to know the
images were present on his disk because he had tried to delete
the files, yet failed to do so. Id. at 745. The jury was
instructed to find whether “[1] . . . Lacy knowingly possessed
‘the matters charged’ and [2] . . . those ‘matters contained a
visual depiction of a minor engaging in sexually explicit con-
duct.’ ” Id. at 747 (quoting jury instructions); see also id. at
748 n.9 (full text of jury instructions). But the instructions
failed to “require a finding that Lacy knew the matters con-
tained the visual depictions.” Id. at 747 (emphasis in original).
Applying United States v. X-Citement Video, Inc., 513 U.S.
64, 72-73 (1994),16 we held that the instructions, by failing to
  16
    In X-Citement Video, the Supreme Court held 18 U.S.C. § 2252
requires the government to prove the defendant’s knowledge that the per-
former depicted is a minor because this is “the crucial element separating
legal innocence from wrongful conduct.” Id., 513 U.S. at 72-73.
8284               UNITED STATES v. ROMM
require a finding that Lacy knew the files were on his disks,
omitted an element of the offense. See Lacy, 119 F.3d at 747
(“[A] defendant may be convicted under § 2252(a)(4)(B) only
upon a showing that he knew that the matter in question con-
tained an unlawful visual depiction.”). Without addressing
whether this error was “plain” or prejudicial, we affirmed at
step four of Olano because of the overwhelming evidence of
Lacy’s knowledge. See Lacy, 119 F.3d at 749-50.

   [13] Here, the jury instructions on knowing possession of
child pornography omitted the same element of knowledge we
addressed in Lacy. The entire instructions on knowing posses-
sion read as follows:

    Defendant Stuart Romm is charged in Count 2 of the
    Indictment with Knowing Possession of Child Por-
    nography, in violation of Title 18, United States
    Code, Section 2252A(a)(5)(B). In order for Defen-
    dant Romm to be found guilty of that charge, the
    Government must prove each of the following ele-
    ments beyond a reasonable doubt:

    First, That Defendant Stuart Romm knowingly pos-
    sessed a laptop computer with a hard drive that con-
    tained three or more images of child pornography;

    Second, That the images of child pornography know-
    ingly possessed by Defendant Stuart Romm, had
    been mailed, shipped, or transported in interstate or
    foreign commerce by any means, including by com-
    puter.

    A person has possession of something if the person
    knows of its presence and has physical control of it,
    or knows of its presence and has the power and
    intention to control it.
                        UNITED STATES v. ROMM                          8285
(Third emphasis added.) Just as in Lacy, the instructions
failed explicitly to require the jury to find whether Romm
knew images of child pornography were present on his disk.

  Furthermore, the jury sent out a note after six hours of
deliberations expressing confusion over the Lacy standard.
The note read:

       We need clarification on the [Possession] Charge.
       Are we trying to determine if Mr. Romm knew that
       he possessed three or more images could [sic] be
       found on his hard drive. Or is simply viewing pic-
       tures considered knowing of its [sic] presence and
       being in control of it.

The court, with the affirmative agreement of both counsel,17
referred the jury back to the original, flawed instructions and
told the jury that no further guidance could be given.

   The government contends that the instructions are distin-
guishable from the instructions given in Lacy because of the
second instruction’s reference to “images . . . knowingly pos-
sessed by Romm.” But this phrase is in fact a peremptory
instruction that Romm knowingly possessed the unlawful
images; not that the jury should determine whether he know-
  17
     The government argues that Romm’s affirmative agreement to this
response waives any right to challenge the jury instructions under the doc-
trine of “invited error.” While the Seventh Circuit has applied waiver in
similar circumstances, see United States v. Askew, 403 F.3d 496, 505-06
& n.3 (7th Cir. 2005), we have limited the doctrine of invited error to
cases where “the record reflects that the defendant was aware of the omit-
ted element [in the jury instructions] and yet relinquished his right to have
it submitted to the jury.” United States v. Perez, 116 F.3d 840, 845 (9th
Cir. 1997) (en banc); see also United States v. Alferahin, 433 F.3d 1148,
1154 n.2 (9th Cir. 2005) (refusing to apply invited error where it appeared
that “both defense counsel and the district court were operating under a
misapprehension of the applicable law”). Here, since nothing in the record
suggests that Romm or his trial counsel were aware of the element omitted
from the jury instructions, invited error does not apply.
8286                   UNITED STATES v. ROMM
ingly possessed them. The jury was told that they only needed
to find whether the images that Romm “knowingly possessed”
had a nexus to interstate commerce. Rather than requiring a
finding that Romm knowingly possessed the images, the
instructions dictated this finding.

   [14] Given that we squarely addressed the same issue in
Lacy, we conclude that the instructions were in error and that
the error was “plain.”18 We assume, without deciding, that the
omission of the knowledge element affected Romm’s substan-
tial rights. We also assume, without deciding, that the district
court’s failure to supplement the flawed instructions was
plainly an abuse of discretion. See United States v. Southwell,
432 F.3d 1050, 1053 (9th Cir. 2005) (“Failure to provide the
jury with a clarifying instruction when it has identified a legit-
imate ambiguity in the original instructions is an abuse of dis-
cretion.”). Even so, we nonetheless may affirm if the record
contains “strong and convincing evidence” that the missing
element of the crime was adequately proved by the prosecu-
tion, such that it is “extremely unlikely” that a properly
instructed jury would not have convicted. See United States
v. Perez, 116 F.3d 840, 848 (9th Cir. 1997) (en banc). Here,
while Romm disputed whether he knew the images were
being stored to the cache, the evidence of his knowledge of
the presence of the visual depictions in his cache and their
content was overwhelming.

  When stopped and interviewed by ICE, Romm was in a
hurry to continue his travels and asserted that the laptop con-
  18
    We note that the Ninth Circuit Model Jury Instructions incorporate
Lacy’s requirement that the defendant know the images are on his disk.
See Model Criminal Jury Instruction 8.154 (2003) (instructing the jury to
determine, “[f]irst, that the defendant knowingly possessed [books] [maga-
zines] [periodicals] [films] [video tapes] [matters] which the defendant
knew contained [a] visual depiction[s] of [a] minor[s] engaged in sexually
explicit conduct.”) (emphasis added). While these instructions are for pos-
session of child pornography under 18 U.S.C. § 2252 rather than 18
U.S.C. § 2252A, both versions of the statute are materially the same.
                      UNITED STATES v. ROMM                       8287
tained his company’s proprietary software. He also acknowl-
edged Canadian authorities knew about his prior conviction.
It was against this background that Romm acknowledged hav-
ing “lapses” from his “therapy,” and viewing images of child
pornography. He also acknowledged to Agent Swenson that
he had “saved” and viewed the images, for up to five minutes,
but claimed to have deleted them. Importantly, he said he had
“saved” or “downloaded” the images to his computer in Las
Vegas.

   After Agent Macho confronted Romm with Swenson’s
relation that ten images of child pornography had been found19
and questioned Romm as to why he had lied to Macho, Romm
did not look surprised, or state he was surprised; rather, he let
his shoulders slump and looked down at the ground rather
than maintain eye contact with Agent Macho, in a demeanor
that Agent Macho described as “confessional.” Then, Romm
stated that “he knew [they] were gonna find something on the
computer.”

   In addition to his statements, the forensic analysis of
Romm’s computer showed that he had erased his internet his-
tory at 2:25 p.m. on February 2, 2004, the same afternoon he
was placed on a flight back to Seattle. Romm’s internet cache
was completely empty, and the government’s expert opined
through his experience and training that Romm had manually
deleted the files or instructed his browser to empty it. There-
fore, the forensic evidence strongly corroborated Romm’s
direct admission that he knew the images were on his disk.

  [15] In sum, because of the overwhelming evidence of
Romm’s knowledge, we decline to exercise our discretion to
correct the plain error in the jury instructions on knowing pos-
session.
  19
    This evidence came in without an objection to its being hearsay.
8288                UNITED STATES v. ROMM
       IV.   ENHANCED MANDATORY MINIMUM
                    SENTENCES

   [16] At sentencing, the government claimed Romm’s prior
convictions under Florida law for promoting sexual perfor-
mance by a child and child exploitation by means of a com-
puter were predicate offenses under 18 U.S.C. § 2252A(b).
The district court found the Florida statutes were overly
broad, but also that Romm’s convictions qualified as predi-
cate offenses under the modified categorical approach. The
parties agreed at argument that the categorical approach
applies but that the record currently does not support the sen-
tence enhancement. In accordance with their agreement, we
vacate Romm’s sentences and remand for resentencing on an
open record, allowing the government to supplement the
record necessary to apply the modified categorical approach.

                      CONCLUSION

   In sum, we hold first that the ICE’s forensic analysis of
Romm’s laptop was permissible without probable cause or a
warrant under the border search doctrine. Second, we hold
there was sufficient evidence for the jury to find the images
in Romm’s internet cache were visual depictions, and that he
both received and possessed these images. Third, we hold the
district court’s refusal of Romm’s proffered instruction defin-
ing “visual depiction” was not error because the instructions
defining possession adequately covered Romm’s theory of the
case. Fourth, while we find the instructions on “knowing pos-
session” were plainly in error under our decision in Lacy, we
decline to reverse Romm’s conviction due to the overwhelm-
ing evidence of the required knowledge. Fifth, we vacate
Romm’s sentences and remand for resentencing in accordance
with the stipulation reached by the parties.

  Accordingly, Romm’s convictions are AFFIRMED. His
sentences are VACATED, and the case is REMANDED.
