FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

                                         No. 22-30177
UNITED STATES OF AMERICA,
                                            D.C. No.
             Plaintiff-Appellee,
                                         1:21-cr-00035-
                                             SPW-1
 v.

ANGELO COREY STACKHOUSE,

OPINION

             Defendant-Appellant.

      Appeal from the United States District Court
              for the District of Montana
       Susan P. Watters, District Judge, Presiding

        Argued and Submitted December 4, 2023
                   Portland, Oregon

                  Filed June 27, 2024

Before: Marsha S. Berzon, Jacqueline H. Nguyen, and Eric
               D. Miller, Circuit Judges.

               Opinion by Judge Berzon
2                       USA V. STACKHOUSE


                          SUMMARY *


                         Criminal Law

    The panel affirmed Angelo Corey Stackhouse’s
convictions for kidnapping a minor using a means or
instrumentality of intrastate commerce, in violation of

(a)(1), 1201(g), and 3559(f)(2), and
transportation of a person across state lines with intent to
engage in illegal sexual activity, in violation of 

(a).
    Rejecting Stackhouse’s argument that his kidnapping
conviction violates the Commerce Clause, the panel held
that the application of the federal kidnapping statute,
§ 1201(a), to an intrastate kidnapping is constitutional where
the defendant uses a cellphone—an instrumentality of
interstate commerce—in furtherance of the offense.
    The panel further held that the government presented
sufficient evidence of Stackhouse’s intent to commit sexual
assault when he transported the victim of his assault across
state lines in violation of § 2421.
    In a concurrently filed memorandum disposition, the
panel resolved Stackhouse’s conviction for kidnapping an
Indian person within the boundaries of a reservation, in
violation of 

, 1201(a)(1)-(2), 1201(g), and
3559(f)(2).




*
 This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
                      USA V. STACKHOUSE                      3


                         COUNSEL

Zeno B. Baucus (argued), Bryan T. Dake, and Tim Tatarka,
Assistant United States Attorneys; Jesse A. Laslovich,
United States Attorney; Office of the United States Attorney,
District of Montana, Billings, Montana; for Plaintiff-
Appellee.
Constance Van Kley (argued), Upper Seven Law, Helena,
Montana, for Defendant-Appellant.

OPINION

BERZON, Circuit Judge:

     Angelo Corey Stackhouse was convicted after a bench
trial on several counts related to the sexual abuse and
mistreatment of minor and adult women, including
kidnapping a minor and transporting a person across state
lines with the intent to engage in illegal sexual activity. The
kidnapping charge involved driving a ten-year-old girl to a
hotel to photograph and sexually assault her, using a
cellphone during the commission of the offense. The
interstate transportation charge stemmed from travel with a
nineteen-year-old woman from Montana to Denver, where
Stackhouse sexually assaulted her. This opinion covers the
kidnapping and transporting convictions, specifically:
(1) whether Stackhouse’s kidnapping conviction violates the
Commerce Clause; and (2) whether there is sufficient
4                        USA V. STACKHOUSE


evidence that Stackhouse intended to commit sexual assault
when he travelled across state lines. 1
    We conclude that the application of the federal
kidnapping statute to an intrastate kidnapping is
constitutional where the defendant uses a cellphone—an
instrumentality of interstate commerce—in furtherance of
the offense. We further determine that Stackhouse’s actions
leading up to and during the trip to Denver established that
he had the intent to commit illegal sexual activity when he
transported the victim interstate, even if the intent was
purportedly conditioned upon the victim’s non-compliance
with his demands.
    We affirm the convictions.
    I. Background
        A. Factual Background
   Stackhouse’s convictions stem from the kidnapping and
sexual assault of multiple women and young children
between 2019 and 2020.
             1. V.G.
     In September 2020, Stackhouse picked up V.G., his
girlfriend’s 10-year-old sister, from her home in Billings,
Montana, under the pretense of taking her to get her
computer repaired. Rather than drive to the repair shop, he
drove V.G. to a Dollar Store, where he purchased massage
oil, and then to a local motel. After arriving at the motel,

1
  Stackhouse appeals his conviction for kidnapping an Indian person
within the boundaries of a reservation on evidentiary grounds. 

, 1201(a)(1)–(2), 1201(g), and 3559(f)(2) (Count VI). We
resolve that appeal in a memorandum disposition filed concurrently with
this opinion.
                     USA V. STACKHOUSE                     5


Stackhouse called someone and said, “I got her in the room.”
Stackhouse then proceeded to set up a camera on the bedside
table. He instructed V.G. to get undressed and rubbed oil
over her, and then took photographs of her body. Stackhouse
had a knife and Taser with him and told V.G., “If you scream
no one’s gonna hear you.” He made V.G. perform oral sex,
and then made her lie on top of him. As they were leaving
the motel room, Stackhouse once again spoke with someone
over the phone, telling them: “Okay. I’m finished. I got the
footage.” Cellphone data corroborated V.G.’s testimony
about the timing and location of the incident.
           2. Hannah
    In May 2020, Stackhouse drove from Billings, Montana
to Denver, Colorado with two women, Hannah and Breezy.
Breezy asked Hannah, who was nineteen, to accompany her
on the trip, and Hannah reluctantly agreed. The three
consumed cocaine, supplied by Stackhouse, as they drove.
    Once in Denver, the three met William O’Neill,
Stackhouse’s cocaine dealer, at a hotel. Stackhouse and
O’Neill provided alcohol and more cocaine, which
Stackhouse encouraged Hannah to consume even when she
expressed a desire to stop. After Breezy and O’Neill left the
room, Stackhouse suggested to Hannah that he expected her
to have sex with him as payment for the trip and the drugs.
Hannah reluctantly agreed because she was “scared” and
“just wanted to go home,” and because she felt that if she
“didn’t do what he wanted,” she “didn’t know . . . what was
going to happen.” Stackhouse refused to use a condom when
asked. Stackhouse took a picture of Hannah’s ID during the
trip, which she suspected was “for leverage.”
   Several days after they returned to Billings, Stackhouse
asked Hannah to meet him at a hotel, where they consumed
6                     USA V. STACKHOUSE


cocaine and had sex. Hannah agreed to go “[b]ecause he had
a picture of [her] ID.” Stackhouse then invited Hannah to go
with him on a second trip to Denver. She again agreed
because he “had a picture of [her] ID, and he knew where
[her] parents lived and that [she] lived with [her] parents . . .
[and she] was scared.”
     Stackhouse again provided Hannah with cocaine on the
drive to Denver. This time, they drove directly to O’Neill’s
house. There, Stackhouse instructed Hannah to have sex
with O’Neill while Stackhouse watched. Hannah testified
that “I obviously didn’t want to, but what was I going to
say?” A while later, after Hannah consumed more cocaine,
Stackhouse instructed Hannah to “please [O’Neill] and his
wife.” Hannah had the “[s]ame reaction [she] had the last
time,” implying that she reluctantly complied. Afterwards,
Hannah informed Stackhouse that she had allowed O’Neill
to penetrate her against Stackhouse’s instructions. Over her
objections, Stackhouse anally penetrated her with an object,
telling her “this is what happens when [she doesn’t] listen to
him.” Stackhouse also took pictures, and possibly a video, of
Hannah’s naked body, “in case [she] was to turn on him, for
his attorney.”
    The day after she returned from Denver, Hannah met
Stackhouse at a hotel in Billings, because she “was still
scared.” They had sex and consumed more cocaine, and
Stackhouse instructed her to stay the night at the hotel alone.
Hannah complied, because she “didn’t know if he was going
to check on me and drive by.”
    Hannah testified that she was afraid of Stackhouse, that
he forced her to go to Denver the second time, and that they
had nonconsensual sex in Denver. She also testified that
                      USA V. STACKHOUSE                      7


Stackhouse told her he always carried a gun with him,
although she never saw him with it.
           3. Other Sexual Acts
    The government introduced evidence that Stackhouse
sexually assaulted or threatened three other women. One
woman testified that in September 2019, Stackhouse
approached her at a bar and brought her to a hotel room while
she was high on methamphetamine. Stackhouse punched her
in the head, threatened to further harm her if she did not take
off her clothes, sexually assaulted her, and told her that he
was going to take her to North Dakota to sell her services as
a prostitute. A second woman testified that she met
Stackhouse at a hotel where he was distributing drugs. While
she was high on methamphetamine and semi-conscious,
Stackhouse raped her. A third woman testified that she
received methamphetamine from Stackhouse at a hotel in the
summer of 2020, after which Stackhouse told her that she
“need[ed] to pay for the[] drugs somehow.” After
Stackhouse threatened her at gunpoint, she took off her
clothes and got into the bed. Stackhouse then informed her
that he was not going to rape her, but that he needed to “make
sure [she wasn’t] a snitch.”
       B. Procedural Background
    Stackhouse was indicted on seven charges, including as
relevant here the kidnapping of a person under the age of 18
(V.G.) using a means or instrumentality of interstate
commerce, in violation of 

(a)(1), 1201(g),
and 3559(f)(2) (Count VII) and the transportation of a person
(Hannah) across state lines with intent to engage in illegal
sexual activity, in violation of 

(a) (Count
I).
8                         USA V. STACKHOUSE


     Stackhouse waived his right to a jury trial. After a bench
trial, the district court convicted Stackhouse on all seven
charges. He now appeals his convictions on Counts I and
VII.
    II. Discussion
    Stackhouse brings an as-applied challenge to his
conviction under the federal kidnapping statute, arguing that
the application of the statute to an intrastate kidnapping
violates the Commerce Clause. With respect to his
conviction for transportation across state lines with intent to
engage in illegal sexual activity, he argues that there is
insufficient evidence of the intent element of the crime.
    An as-applied constitutional challenge to a statute is
reviewed de novo. United States v. Mahon, 

 (9th Cir. 2015). Although Stackhouse did not raise his
constitutional challenge below, the government recognizes
that he may raise the issue for the first time on appeal. See
United States v. Parker, 

 (9th Cir. 2014). 2
We review the sufficiency of the evidence supporting a
conviction de novo. United States v. Johnson, 

 (9th Cir. 2017). “For a challenge to the
sufficiency of the evidence following a bench trial, we
review ‘whether, after 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.’” United States v. Laney, 

,


2
  Parker did not address what standard of review applies when a
constitutional challenge is raised for the first time on appeal. Because the
government does not argue that plain-error review applies, and because
we would uphold Stackhouse’s convictions under the less deferential de
novo standard, we review his constitutional challenge de novo.
                          USA V. STACKHOUSE                              9


1106 (9th Cir. 2018) (quoting United States v. Atkinson, 

, 502–03 (9th Cir. 1993) (en banc)). 3
         A. The Kidnapping Statute and the Commerce
            Clause
              1. As-Applied Challenge
    Stackhouse challenges his conviction for the kidnapping
of V.G. on the ground that Congress lacks the power to
criminalize a kidnapping occurring entirely intrastate, where
the statute of conviction proscribes the use of an
instrumentality of commerce in carrying out the kidnapping,
but the kidnapping is not economic in nature and no effect
upon interstate commerce is shown. The government
maintains Stackhouse’s conviction was a valid exercise of
Congress’s power to regulate the instrumentalities of
interstate commerce.
    Article I, section 8 of the Constitution grants Congress
the power “[t]o regulate commerce . . . among the several
states.” United States v. Lopez identified “three broad
categories of activity that Congress may regulate under its
commerce power”: (1) “channels of interstate commerce”;
(2) “instrumentalities of interstate commerce”; and
(3) “activities that substantially affect interstate commerce.”

, 558–59 (1995).




3
  Stackhouse moved for acquittal at the close of the government’s
evidence, albeit on different grounds than those raised here. Although
the defense did not renew the motion after introducing its only witness,
“no motion for acquittal is necessary in a bench trial in order to preserve
for appeal a challenge to the sufficiency of the evidence.” Atkinson, 

.
10                    USA V. STACKHOUSE


    Stackhouse was convicted under the federal kidnapping
statute, which imposes criminal penalties upon:

       Whoever unlawfully seizes, confines,
       inveigles, decoys, kidnaps, abducts, or carries
       away . . . any person, . . . when—the person
       is willfully transported in interstate or foreign
       commerce, . . . or the offender travels in
       interstate or foreign commerce or uses the
       mail or any means, facility, or instrumentality
       of interstate or foreign commerce in
       committing or in furtherance of the
       commission of the offense.

(a)(1). The statute thus identifies three
bases for federal jurisdiction: the transport of the victim
across state lines, the movement of the offender interstate, or
the use of instrumentalities of interstate commerce in
committing or in furtherance of the offense.
    The parties agree Stackhouse did not transport V.G.
across state lines, nor did he otherwise travel in interstate
commerce during the commission of the offense. The
government contends that Stackhouse’s conviction falls
within the second Lopez category: use of instrumentalities of
commerce—asserted to be the cellphone, car, and hotel—in
furtherance of the kidnapping. We conclude that the
application of § 1201(a) was constitutional with respect to
Stackhouse’s use of a cellphone, and so do not consider the
other asserted instrumentalities of commerce.
    Stackhouse agrees that a cellphone is an instrumentality
of interstate commerce, with good reason. “Telephones are
instrumentalities of interstate commerce that fall within the
second Lopez category.” United States v. Nader, 542 F.3d
                         USA V. STACKHOUSE                             11


713, 717 (9th Cir. 2008). We have applied this principle
equally to landlines and cellphones. See United States v.
Clayton, 

 (9th Cir. 1997). 4
    While recognizing that cellphones are instrumentalities
of interstate commerce, Stackhouse contends, first, that
Congress’s commerce power under the second Lopez
category does not reach statutes forbidding “the use of an
instrumentality” to commit a separate offense. According to
Stackhouse, § 1201(a) does not fall within the second Lopez
category because what the statute regulates is kidnapping,
not the instrumentality used to carry out the kidnapping. That
proposition is contrary to the Supreme Court’s modern
Commerce Clause cases, this court’s precedents, and the
holdings of numerous cases from other federal courts of
appeals, as well as the language of § 1201(a).



4
  Courts have found that the transmission of a cellular signal engages
interstate communications equipment. See United States v. Weathers,

 (6th Cir. 1999) (upholding a conviction under the
murder-for-hire statute where the use of a cellphone to conduct an
intrastate call involved the transmission of interstate signals).
Furthermore, under the federal wiretapping statute, 

,
cellular telephone service is considered to be a “wire communication,”
see 

 § 2510(1), because “cellular telephone service, despite its
apparent wireless nature, . . . uses wire and cable connections to connect
calls.” In re Application of the United States for an Ord. Authorizing
Roving Interception of Oral Commc’ns, 

, 1139 (9th Cir.
2003). Calls made via cellphone are transmitted via radio to a cell site,
from which the signals travel over fixed links to a telephone switching
station. S. REP. No. 99-541, at 9, 11 (1986). We need not decide whether
the radio transmission alone would be a sufficient use of interstate
communication facilities, but we note that radio communication has been
subject to federal regulation almost from its inception. See Radio Act of
1927, ch. 169, 

.
12                    USA V. STACKHOUSE


    As to whether the use of a cellphone in furtherance of an
intrastate crime is a sufficient basis under the Commerce
Clause for a federal offense, Lopez emphasized that
“Congress is empowered to regulate and protect the
instrumentalities of interstate commerce . . . even though the
threat may come only from intrastate activities.” 

. Congress’s power extends to instrumentalities of
commerce because they “are the ingredients of interstate
commerce itself.” Gonzales v. Raich, 

 (2005)
(Scalia, J., concurring in the judgment). Forbidding the use
of instrumentalities of commerce, including cellphones, to
further intrastate crime, including kidnapping, is
“regulat[ing]” one aspect of the device—its use in certain
circumstances. U.S. const., art. I, sec. 8. As the Eleventh
Circuit has explained:

       Plainly, congressional power to regulate the
       channels and instrumentalities of commerce
       includes the power to prohibit their use for
       harmful purposes, even if the targeted harm
       itself occurs outside the flow of commerce
       and is purely local in nature. Congress has
       repeatedly used this power to reach criminal
       conduct in which the illegal acts ultimately
       occur intrastate, when the perpetrator uses the
       channels or instrumentalities of interstate
       commerce to facilitate their commission.

United States v. Ballinger, 

 (11th Cir.
2005) (citations omitted).
    Our caselaw confirms that the second Lopez category is
not limited to statutes directly regulating instrumentalities of
commerce. In United States v. Dela Cruz, we upheld 18
                       USA V. STACKHOUSE                         

(e) as applied to a bomb threat conveyed via a
phone call within a U.S. territory. 

 (9th
Cir. 2004). That statute prohibits bomb threats made
“through the use of the mail, telephone, telegraph, or other
instrument of interstate or foreign commerce.” 

(e) (emphasis added). What is regulated by § 844(e) is
the use of a telephone or “other instrument” to make the
threat. Dela Cruz upheld the statute as a valid exercise of
Congress’s power to regulate instrumentalities of commerce
under Lopez. 

; accord United States v.
Corum, 

, 494–95 (8th Cir. 2004); United States
v. Gilbert, 

, 158–59 (1st Cir. 1999).
    United States v. Nader is in accord. 542 F.3d at 717.
Nader upheld convictions under the Travel Act, which
prohibits the “use[ of] the mail or any facility in interstate
commerce, with intent to—(1) distribute the proceeds of any
unlawful activity; or (2) commit any crime of violence to
further any unlawful activity; or (3) otherwise promote . . .
any unlawful activity.” 

(a). 5 Like the bomb
threat statute, the Travel Act regulates the use of
instrumentalities of commerce to commit a distinct offense,
not the instrumentality itself without regard to its use. The
defendants in Nader, for example, were convicted based
upon their use of phone calls to run a prostitution business.
542 F.3d at 715–16. The appellants, Nader said, “correctly
d[id] not contest that Congress has the power to regulate
intrastate telephone calls” used to further unlawful intrastate
activity because “[t]elephones are instrumentalities of
interstate commerce that fall within the second Lopez

5
   “Unlawful activity” under the Travel Act includes gambling,
distribution of controlled substances, and prostitution, among other
activities. 

(b).
14                        USA V. STACKHOUSE


category.” 

 (emphasis omitted). Both Dela Cruz
and Nader, then, recognize that proscribing the use of
telephones and other instrumentalities of commerce to
commit or further intrastate crime is regulation of
instrumentalities of commerce valid under Lopez’s second
category.
    The kidnapping statute provides that “[w]hoever . . . uses
the mail or any means, facility, or instrumentality of
interstate or foreign commerce in committing or in
furtherance of the commission of the offense” is subject to
criminal penalties, 

(a) (emphasis added),
paralleling the language of the bomb threat statute and the
Travel Act. The parallel language to that in Dela Cruz and
Nader compels parallel results, leading us to conclude the
kidnapping statute is valid under the Commerce Clause
where a cellphone is used in committing or in furtherance of
the kidnapping. 6
    Other circuits have similarly recognized that “as long as
the instrumentality itself is an integral part of an interstate
system, Congress has power, when necessary for the
protection of interstate commerce, to include intrastate
activities within its regulatory control.” Kerbs v. Fall River
Indus., Inc., 

 (10th Cir. 1974), abrogated
on other grounds by Cent. Bank of Denver, N.A. v. First
Interstate Bank of Denver, N.A., 

 (1994). The
Fifth Circuit in United States v. Marek, for example,

6
  We note that neither Nader nor Dela Cruz required a showing that the
transmission of the particular telephone call at issue was interstate rather
than intrastate. No issue about the nature of the cellphone transmission
or origin has been raised here. See Nader, 542 F.3d at 716; Dela Cruz,

; see also United States v. Giordano, 

, 38–41
(2d Cir. 2006); United States v. Richeson, 

, 660–61 (7th Cir.
2003); United States v. Marek, 

 (5th Cir. 2001).
                      USA V. STACKHOUSE                     15


reasoned that “[w]hen Congress regulates and protects under
the second Lopez category, . . . federal jurisdiction is
supplied by the nature of the instrumentality or facility used,
not by separate proof of interstate movement.” 

. And in reviewing a conviction under 

(b), prohibiting the use of “any facility or means” of
interstate commerce to entice minors into sexual activity, the
Eleventh Circuit noted that the Commerce Clause power
“includes     prohibiting    the    use    of     commercial
instrumentalities for harmful purposes even if the targeted
harm ‘occurs outside the flow of commerce’ and ‘is purely
local.’” United States v. Faris, 

, 758–59 (11th
Cir. 2009) (per curiam) (quoting Ballinger, 

).
    Our conclusion that the Commerce Clause permits
Congress to regulate intrastate kidnappings in particular
where an instrumentality of commerce is used intrastate also
aligns with decisions of other courts of appeal. The Sixth
Circuit has concluded that the commerce power extends to
the intrastate use of a cellphone in committing an intrastate
kidnapping. United States v. Windham, 

, 1011–
13 (6th Cir. 2022). Similarly, the Tenth Circuit has upheld
convictions under § 1201(a)(1) where the defendants used a
cellphone, the Internet, and a GPS device to carry out a
kidnapping intrastate. United States v. Morgan, 

, 1032 & n.8 (10th Cir. 2014).
    We conclude that the application of the kidnapping
statute here falls within the second Lopez category. We
therefore need not address Stackhouse’s argument that the
government was required to show that the kidnapping was
economic in nature or had a substantial effect on interstate
commerce. Whether an activity is “economic in nature” is
relevant to determining whether an activity has a substantial
16                    USA V. STACKHOUSE


effect on interstate commerce under Lopez’s third category,
see Taylor v. United States, 

 (2016);
United States v. Morrison, 

, 610–13 (2000);
Lopez, 514 U.S. at 559–60, not to the “instrumentality of
commerce” category. Where Congress regulates an
instrumentality of commerce under the second Lopez
category, “no further inquiry is necessary to determine that
their regulation . . . is within the Commerce Clause
authority.” Clayton, 

. More specifically,
“[b]ecause a telephone is an instrumentality of interstate
commerce, no substantial effects inquiry is needed.” Dela
Cruz, 

; see also Corum, 

.
           2. Sufficiency of the Evidence
    Stackhouse contends that there is insufficient evidence
that the kidnapping was economic in nature or had a
substantial relation to interstate commerce. As we concluded
above, because Stackhouse’s conviction falls within the
second Lopez category as a regulation of the
instrumentalities of interstate commerce, the government
was not required to prove that the kidnapping was economic
in nature or had a substantial relation to interstate commerce.
    Stackhouse does not argue that the government
presented insufficient evidence that he used a cellphone, or
any other instrumentality of commerce, “in committing or in
furtherance of the kidnapping.” 

(a). We
therefore do not consider that issue.
       B. Transportation Across State Lines
    Stackhouse next challenges his conviction under 

(a), contending that there was insufficient
evidence that he travelled interstate with the intent to commit
sexual assault.
                           USA V. STACKHOUSE                                17


              1. Intent Element
      Section 2421(a) applies to anyone who “knowingly
transports any individual in interstate or foreign commerce
. . . with intent that such individual engage in prostitution, or
in any sexual activity for which any person can be charged
with a criminal offense, or attempts to do so.” 

(a). 7
    To satisfy the intent element under § 2421(a), “the
government must prove beyond a reasonable doubt that a
dominant, significant, or motivating purpose of the
transportation of the individuals was to engage in criminal
sexual activity.” United States v. Flucas, 

 (9th Cir. 2022). The criminal purpose need not be the
“sole purpose” of the interstate travel, 

, nor a but-
for cause of the transportation, United States v. Lindsay, 931

7
   The Mann Act, 

ch. 395, 

 (1910)
(codified as amended at 18 U.S.C. §§ 2421–24), was adopted to address
the conscription of women into prostitution. See Mortensen v. United
States, 

 (1944). Before it was amended in 1986, § 2421
prohibited the “knowing[] transport[ation] in interstate . . . commerce . .
. [of] any woman or girl for the purpose of prostitution or debauchery . . .
or with the intent and purpose to induce, entice, or compel such woman
or girl to become a prostitute.” United States v. Sabatino, 

 (1st Cir. 1991) (quoting ch. 395, 36 Stat. at 825). The 1986
amendments altered the statutory language to apply to “any individual,”
rather than “any woman or girl,” and to alter the objects of the
defendant’s intent; rather than debauchery, the intended activity must be
“prostitution, or . . . any sexual activity for which any person can be
charged with a criminal offense.” Id. (quoting 

(b)(1),

, 3511–12 (1986)). Both versions of the statute require
intent to engage in illicit or criminal activity. Cases interpreting the intent
element under the pre-1986 statute apply equally to the amended § 2421,
as well as to the parallel provision under § 2423, which regulates the
interstate transportation of minors with intent to engage in criminal
sexual activity, among other offenses.
18                       USA V. STACKHOUSE


F.3d 852, 864 (9th Cir. 2019) (analyzing 

(b)).
    Contrary to the parties’ assertions, a conviction under
§ 2421 does not require that criminal sexual activity in fact
occurred. “[G]uilt under the Mann Act turns on the purpose
which motivates the transportation, not on its
accomplishment.” Cleveland v. United States, 

 (1946). Because the act regulated is the “transport[ation
of] any individual in interstate or foreign commerce,” the
offense is complete once the transportation occurs. See
Wilson v. United States, 

, 570–71 (1914);
United States v. Beach, 

 (1945); Reamer v.
United States, 

 (8th Cir. 1963); United States
v. Marks, 

, 18–19 (7th Cir. 1959).
    In any event, Stackhouse agrees that the government
offered evidence that would support a conviction for illegal
sexual activity under Colorado law with respect to the
nonconsensual anal penetration he committed against
Hannah. 8 His argument is that he did not form the intent to
commit the assault, or any other illegal sexual act, before the
interstate travel. 9 Instead, he asserts that he formed the intent

8
  According to the government, Stackhouse could have been charged
with criminal sexual assault under Colorado Revised Statute § 18-3-
402(1)(a) (2013). At the time of the offense, § 18-3-402(1)(a) read: “Any
actor who knowingly inflicts sexual intrusion or sexual penetration on a
victim commits sexual assault if: The actor causes submission of the
victim by means of sufficient consequence reasonably calculated to
cause submission against the victim’s will.”
9
  Although Mortensen stated that the intent must “exist before the
conclusion of the interstate journey,” 

, we later
“disapprove[d] of the use of [Mortensen’s] language relative to the time
an unlawful intent must be formed,” instead concluding that “[t]he
                         USA V. STACKHOUSE                             19


to commit the assault immediately before it occurred—and
after the interstate transportation was complete—when
Hannah informed him that she had had penetrative sex with
O’Neill against Stackhouse’s instructions.
    In appropriate circumstances, the fact that an assault later
occurred could perhaps be sufficient by itself to permit an
inference that a defendant intended to commit the offense
before crossing a state line. We need not consider whether
such a bare inference is appropriate here, as the defendant’s
conduct both in the past and immediately before and after
the interstate journey provides sufficient insight into his state
of mind at the time of transportation to allow a finding
beyond a reasonable doubt that Stackhouse intended
Hannah’s sexual assault when he drove into Colorado.
    For one thing, caselaw establishes that a pattern of
sexually assaultive conduct can support an inference of
intent to commit sexual assault while travelling interstate
before the assault. In analyzing a conviction for
transportation for the purpose of prostitution under § 2421,
this court in Baker v. United States stated: “Among the
circumstances which may be considered in determining
whether such an intent existed . . . are that there were other
similar activities by the accused, showing a pattern of
conduct, [and] that, at the end of the journey the female was
taken by the accused to a house of prostitution.” 

 (9th Cir. 1962) (internal citation omitted). In United


preferable practice is to instruct that the unlawful intent must be formed
before crossing a state line.” United States v. Fox, 

(9th Cir. 1970). This timing distinction makes no difference here.
Nothing in the record suggests that Stackhouse had a different state of
mind when crossing into Colorado than he did at the conclusion of his
journey at O’Neill’s home.
20                       USA V. STACKHOUSE


States v. Wesson, we similarly concluded that the purpose
element under § 2421 was met where the defendant
repeatedly raped and beat the victim and offered her services
as a prostitute over the radio while travelling by truck across
state lines. 

 (9th Cir. 1986) (per curiam).
And in United States v. Kinslow, we found sufficient
evidence of the defendant’s intent when transporting a minor
across state lines to commit sexual misconduct upon arrival,
in violation of § 2423, where the defendant sexually
assaulted the minor victim’s mother shortly before the act of
transport. 

, 967–68 (9th Cir. 1988), overruled
on other grounds by United States v. Brackeen, 

 (9th Cir. 1992); see also Tedesco v. United States,

, 741–42 (9th Cir. 1941); United States v. Snow,

 (7th Cir. 1974); Marks, 

; Dunn
v. United States, 

 (10th Cir. 1951).
    Evidence of Stackhouse’s interactions with other women
similarly supports inferring his intent before arriving in
Colorado to sexually assault Hannah. The government
introduced testimony by three women whom Stackhouse
sexually assaulted or threatened to assault in 2019 and 2020,
under circumstances similar to those surrounding his
interaction with Hannah. 10 All three encounters took place
in hotel rooms and involved women under the influence of

10
   The government provided notice of its intent to introduce evidence of
prior acts under Federal Rules of Evidence 404(b) and 413. Evidence of
prior acts may be introduced under Rule 404(b) for the limited purpose
of proving intent. United States v. Ayers, 

 (9th Cir.
1991). Under Rule 413, “a party may admit evidence of a sexual assault
in order to prove that the defendant has the propensity to commit another
sexual assault.” United States v. Redlightning, 

, 1119–20
(9th Cir. 2010). The defense does not argue on appeal that such evidence
was improperly admitted or challenge the constitutionality of Rule 413.
                     USA V. STACKHOUSE                     21


drugs, some provided by Stackhouse. Stackhouse suggested
to one of the victims that she owed him sexual favors as
repayment for the drugs. He threatened one woman at
gunpoint, and indicated to another that he had a gun.
Stackhouse raped one of the victims while she was
unconscious, and another after threatening to beat her and to
sell her into prostitution. The testimony provides ample
evidence that Stackhouse repeatedly forced women into
sexual encounters using violence and coercion. A factfinder
could rely in part on such evidence to infer that Stackhouse
had the intent of similarly engaging in nonconsensual sex
with Hannah when he brought her to Denver.
    Considered in the light most favorable to the
prosecution, Stackhouse’s actions leading up to and during
the second trip to Denver further support an inference of an
intent to sexually manipulate, coerce, and control Hannah
upon arrival. During the initial trip, Stackhouse plied the
victim with cocaine and alcohol and told her that she owed
him sexual favors as repayment. Hannah accompanied
Stackhouse on the second trip to Denver because she felt
“scared” of him, in part because he had taken a photo of her
ID and knew where she lived. During the second trip,
Stackhouse drove Hannah directly to O’Neill’s house, where
he instructed her to perform sex acts against her wishes. He
then engaged in non-consensual sex as a form of punishment
for disobeying his instructions related to Hannah’s sexual
interactions with others. Taken as a whole, a factfinder could
conclude that Stackhouse’s actions were calculated to coerce
Hannah into sexual encounters against her will. That is,
considering the context of the trip, it is “apparent that
[Stackhouse] contemplated that the sex might not be
consensual and that force would be necessary.” United
22                   USA V. STACKHOUSE


States v. Bonty, 

 (7th Cir. 2004) (upholding
a conviction under § 2423).
           2. Contingent Intent
    Even if Stackhouse intended when crossing into
Colorado to sexually assault Hannah under some
circumstances, Hannah’s account of what happened—
including that Stackhouse told her “this is what happens
when [she doesn’t] listen to him” before anally penetrating
her—suggests that Stackhouse may have intended to
sexually assault her only if she did not comply with his
directions and demands. So the question arises whether to be
convicted under § 2421, Stackhouse must have had an
unconditional intent to commit a sexual crime when crossing
the state line.
    In Holloway v. United States, the Supreme Court
recognized contingent intent as sufficient for a criminal
conviction under the federal carjacking statute, 

. See 

, 6–8, 12 (1999). That statute
criminalizes the forceful taking of a motor vehicle “with the
intent to cause death or serious bodily harm.” 

. Holloway concluded that “a person who points a gun
at a driver, having decided to pull the trigger if the driver
does not comply with a demand for the car keys, possesses
the intent, at that moment, to seriously harm the driver.” 

 (emphasis added). To require the defendant to
possess an unconditional intent to kill or harm “would
improperly transform the mens rea element . . . into an
additional actus reus component of the carjacking statute.”

.
    The Court based its conclusion on the reasoning that
“intent” is most naturally read to encompass conditional as
well as unconditional intent, as well as on the overall
                      USA V. STACKHOUSE                     23


purpose of the statute—to deter criminal activity—and the
assumption that Congress would be familiar with the
established principle that intent may be conditional. 

 at 7–
9. Those justifications apply equally to the federal
kidnapping statute.
    The Holloway Court noted, in particular, that state courts
have long upheld convictions based upon contingent intent.

 at 10 & n.9. In People v. Vandelinder, a Michigan
appellate court, for instance, upheld a conviction for
solicitation to murder where the defendant instructed a hired
kidnapper to kill his wife if she declined the terms of his
demands. 

, 450–51 (1992). In
Commonwealth v. Richards, the Massachusetts Supreme
Judicial Court similarly determined that an intent to murder
“should it become necessary to effectuate the robbery or
make good an escape” was sufficient for assault with intent
to murder. 

 (1973) (emphasis added). In
People v. Miley, a California appellate court upheld a
conviction for solicitation to murder where the defendant
gave an instruction to kill the witnesses if they were home,

, 33–34 (1984); and in People v.
Connors, the Illinois Supreme Court approved of a
conviction for assault with intent to murder of a union
organizer who threatened to kill a worker if he did not walk
off the job, 

 (1912). The same principle
has been adopted by the Model Penal Code (MPC), which
specifies “[w]hen a particular purpose is an element of an
offense, the element is established although such purpose is
conditional, unless the condition negatives the harm or evil
sought to be prevented by the law defining the offense.”
General Requirements of Culpability, Model Penal Code
§ 2.02(6). See also 

 (adopting
24                     USA V. STACKHOUSE


similar language to the MPC); 

(same); 

(f) (same).
    That principle applies here. On the evidence before us,
Stackhouse’s intent can arguably be characterized as an
intent to have sex with Hannah without her consent if she did
not comply with his demands and directions. The condition
imposed was not one that “negatives the harm or evil sought
to be prevented,” Model Penal Code § 2.02, as the condition
that the victim have sex with Stackhouse regardless of her
consent is the kind of harm sought to be prevented by the
Mann Act. The intent element is not negated “by requiring
the victim to comply with a condition the defendant has no
right to impose,” Holloway, 

, here, the
condition that she have sex with another man (and his wife)
in the way Stackhouse directed. So the fact Stackhouse may
not have had an unconditional intent to commit sexual
assault when he drove Hannah to Colorado does not
undermine a finding of intent under § 2421. Accord Bonty,

.
    The Seventh Circuit specifically so held in a closely
parallel case. In Bonty, the defendant argued that he “only
intended to have consensual sex with [the victim]” when
crossing state lines, and that “it wasn’t until after the [victim]
unexpectedly declined his sexual advances” after he had
arrived at his destination “that it occurred to him to use
force.” 

 Based on the circumstances of the encounter, the
court, as noted earlier, concluded that the defendant had
“contemplated that the sex might not be consensual and that
force would be necessary.” 

 Thus, the intent element of
§ 2421 was satisfied because the defendant “intended to
have sex with [the victim] . . . either (1) with her consent, or
(2) by force.” Id.
                     USA V. STACKHOUSE                     25


    In sum, that Stackhouse may have intended to assault
Hannah contingently—if the victim did not fully comply
with his demands—is sufficient to meet the intent element
of § 2421. Combining the adequacy of contingent intent with
the evidence the government introduced—establishing
Stackhouse’s pattern of assaultive behavior and prior
interactions with other women, as well as his behavior
leading up to and during his second trip to Denver with
Hannah—there was sufficient evidence to convict
Stackhouse of the § 2421 violation. We affirm that
conviction.
   III. Conclusion
    We hold that the application of § 1201(a) to an intrastate
kidnapping where the defendant uses a cellphone in
furtherance of the offense is a valid exercise of Congress’s
authority to regulate the instrumentalities of interstate
commerce. We further hold that the government presented
sufficient evidence of the defendant’s intent to commit
sexual assault when he transported the victim of his assault
across state lines in violation of § 2421.
   AFFIRMED.