 United States Court of Appeals
          FOR THE DISTRICT OF COLUMBIA CIRCUIT



Submitted March 20, 2020                 Decided June 26, 2020

                         No. 19-3026

                 UNITED STATES OF AMERICA,
                         APPELLEE

                               v.

                         DAVID LIEU,
                         APPELLANT


         Appeal from the United States District Court
                 for the District of Columbia
                    (No. 1:17-cr-00050-1)


     Jonathan Zucker, appointed by the court, was on the briefs
for appellant.

    Daniel Richardson, Attorney, U.S. Department of Justice,
Jessie K. Liu, U.S. Attorney at the time the brief was filed, and
Elizabeth Trosman and Jodi S. Lazarus, Assistant U.S.
Attorneys, were on the brief for appellee.

    Before: ROGERS, GRIFFITH, and KATSAS, Circuit Judges.

    Opinion of the Court filed by Circuit Judge KATSAS.

     KATSAS, Circuit Judge: David Lieu was convicted of
distributing child pornography and traveling across state lines
                               2
to engage in sexual conduct with a nine-year-old girl. We
consider whether the latter conviction must be set aside
because the girl whom Lieu intended to molest was in fact an
FBI fabrication. We also consider whether the district court
permissibly admitted evidence that Lieu had molested his own
stepdaughter several years earlier, when she was between six
and eight years old.

                               I

     The facts of this case are disturbing. On February 3, 2016,
Lieu came across an Internet solicitation that read: “Any other
young perv dads into no limit taboo stuff, shoot me an email …
don’t want to say to[o] much on here.” S.A. 101. Lieu replied
that he was “totally a taboo/pervy dad” and “into that.” S.A.
103. Lieu and the poster, who called himself “John,” continued
an online conversation about their sexual interest in young
girls. John described having oral sex with his nine-year-old
daughter and sent Lieu a picture of her. Lieu responded that
John was a “lucky dog,” S.A. 112, and that the girl looked
“delicious,” S.A. 124.         Lieu also described how his
stepdaughter had “played some” with his erect penis, and the
“anticipation of what she would do next was enough to make
my heart jump out of my chest.” S.A. 146. But he said that
things “never went much farther,” id., and the “play” stopped
about four years ago, when his stepdaughter was about ten
years old, S.A. 112–13. Lieu sent John nine pictures of naked
girls. One was of his stepdaughter at age seven, “getting out of
the shower dripping wet.” S.A. 283. Three were of girls
between the ages of six and twelve, with their genitalia
exposed. Lieu and John agreed to meet the next day in
Washington, D.C., to perform various sex acts on John’s
daughter. On February 4, 2016, Lieu traveled from Maryland,
where he was on a business trip, to D.C. as planned.
                              3
    In fact, “John” was Detective Timothy Palchak, an
investigator with the FBI’s Child Exploitation Task Force.
Palchak had created the solicitation and engaged Lieu as part
an undercover effort to combat child sex abuse. Palchak had
no nine-year-old daughter, and the images that he sent to Lieu
were not pictures of actual children. When Lieu arrived in D.C.
and introduced himself to Palchak, he was promptly arrested.

     During the ensuing investigation, the government
recovered Lieu’s home computer and cellphone. The computer
contained hundreds of images of child pornography, and Lieu’s
browsing history revealed thousands more. The cellphone
contained Lieu’s exchange with Palchak, as well as another
explicit conversation between Lieu and a third party. In that
exchange, Lieu recounted that he “had some experience” with
his stepdaughter: “I can still remember my pounding heart.
Wish it could have gone further than it did.” S.A. 200. On the
morning of February 4, Lieu also reported that he was
“supposed to be getting together” with an eight-year-old
“tonight.” S.A. 201–02. Lieu’s stepdaughter, whom we will
call “E.,” told investigators that Lieu had her touch his
unclothed, erect penis on three occasions when she was
between six and eight years old. She further revealed that,
when she was ten or eleven years old, Lieu entered the
bathroom when she was naked and about to take a shower, put
his hands on her hips from behind, and told her that she was
beautiful.

      Lieu was charged with one count of distributing child
pornography, see 18 U.S.C. § 2252(a)(2), and one count of
traveling in interstate commerce for the purpose of engaging in
illicit sexual conduct with a minor, see id. § 2423(b). Lieu
moved to dismiss the travel count. He argued that section
2423(b) did not apply because his intended victim—Palchak’s
purported nine-year-old daughter—does not exist. The district
                               4
court rejected that argument. It noted that Lieu had “traveled
across state lines for the purpose of engaging in illicit sexual
conduct with a real person,” despite not knowing that the
intended victim was fictitious. United States v. Lieu, No. 17-
0050, 2018 WL 5045335, at *4 (D.D.C. Oct. 17, 2018).

     Before trial, the government sought a ruling that E. could
testify about Lieu’s abuse. The district court held the testimony
admissible for two purposes. First, under Federal Rule of
Evidence 404(b), it was admissible to prove Lieu’s knowledge
and intent with respect to both offenses. United States v. Lieu,
298 F. Supp. 3d 32, 55 (D.D.C. 2018). Second, under Rule
414(a), it was admissible on the distribution count for any
purpose, including to prove that Lieu had a propensity to
distribute child pornography. Id. at 58–59. Applying Rule 403,
the court further held that the probative value of E.’s testimony
was not substantially outweighed by any danger of unfair
prejudice or confusion. Id. at 55–57, 59–60.

     In the government’s case-in-chief, Detective Palchak
testified about his exchanges with Lieu. Among other things,
Palchak read a transcript of Lieu’s statements describing his
past abuse of E. Other officers described the child pornography
recovered from Lieu’s computer and the exchanges recovered
from his cellphone, including Lieu’s exchanges with Palchak
and the third party. The government introduced select images
of child pornography from Lieu’s computer. Finally, E., then
sixteen years old, recounted Lieu’s past abuse.

      Lieu testified in his own defense. He claimed that he was
only pretending to have a sexual interest in children, in order
to determine whether Palchak had such an interest. According
to Lieu, if Palchak turned out to be a child predator, Lieu would
have reported him to the police, and if not, Lieu would have
tried to recruit Palchak to work for his insurance company. As
                                5
part of the ruse, Lieu claimed to have made up his sexual
attraction to E., who he says instigated the touching incidents
over his objection. Lieu admitted sending Palchak various
images of naked girls, again as part of his ruse. But he
disclaimed any knowledge of the three sexually explicit images
sent to Palchak, which he said must have reflected a computer
error. And he claimed that the pornographic images on his
home computer had been downloaded by mistake, as he was
experimenting with ways to compile large amounts of
information at once.

    The jury convicted Lieu on both counts. The district court
sentenced him to 286 months of imprisonment, followed by ten
years of supervised release.

                                II

     Lieu first argues that he committed no travel offense
because his intended victim—Palchak’s purported nine-year-
old daughter—does not exist. Lieu contends that the district
court thus erred in denying his motion to dismiss the travel
count. We review this statutory question de novo. See United
States v. Hite, 769 F.3d 1154, 1160 (D.C. Cir. 2014).

     At the time of Lieu’s offense, section 2423(b) provided
that “[a] person who travels in interstate commerce ... for the
purpose of engaging in any illicit sexual conduct with another
person shall be fined under this title or imprisoned not more
than 30 years, or both.”1 Illicit sexual conduct includes any
sexual act with a minor that would violate certain other statutes,
id. § 2423(f)(1), one of which prohibits adults from knowingly

    1
      Congress later amended section 2423(b) by removing “for the
purpose” and substituting “with a motivating purpose.” See Pub. L.
No. 115-392, § 14, 132 Stat. 5250, 5256 (Dec. 21, 2018). The
amendment was not retroactive and thus does not apply here.
                               6
engaging in any sexual act with another person under the age
of 12, id. § 2241(c) & (d). Thus, if Palchak had a nine-year-
old daughter, Lieu could be convicted for traveling with an
intent to engage in sexual conduct with her.

     Lieu contends that he could not be convicted because
Palchak’s purported daughter was not an actual person. Lieu
stresses that section 2423(b) requires an intent to engage in
sexual conduct with “another person.” He reasons that this
“person” must be an actual human being, especially because
section 2423(b) also uses the word “person” to denote the
perpetrator, who likewise must be an actual human.

     Lieu is correct that section 2423(b) uses “person” to mean
an actual person, but that premise does not help him. Section
2423(b) requires that the defendant travel in interstate
commerce with a particular state of mind—“for the purpose of
engaging in any illicit sexual conduct with another person”
(emphasis added). Lieu easily satisfied this state-of-mind
requirement: When he traveled from Maryland to D.C. on
February 4, 2016, he did intend to engage in illicit sexual
conduct with an actual child, rather than with a computer-
generated image or with a figment of Palchak’s imagination.
And because Lieu intended to have sexual contact with an
actual child, he violated the statute even if he was mistaken
about the physical attributes—or even the existence—of the
child. In short, the statute requires an actual person, but only
in the mind of the defendant.

     Lieu also notes that an immediately adjacent statute makes
it unlawful for any “person” to transport an “individual” in
interstate commerce with an intent that the “individual” engage
in prostitution. 18 U.S.C. § 2423(a). Lieu reasons that related
statutes should be construed harmoniously; and because
section 2423(a) requires an actual victim, section 2423(b) must
                               7
as well. But the provisions work differently. Section 2423(a)
requires a live victim because the defendant, to commit the
prohibited act, must transport another “individual” in interstate
commerce. Section 2423(b) does not require a live victim
because the defendant need only himself travel in interstate
commerce, and because the “person” to be victimized must
exist only in the defendant’s mind at the time of the travel.

     Our analysis tracks the settled principle that impossibility
is not a defense to an inchoate crime, so long as the defendant
had the requisite state of mind to commit the underlying
offense. See, e.g., United States v. Williams, 553 U.S. 285, 300
(2008); W. LaFave, 2 Substantive Criminal Law § 11.5(a)(2)
(3d ed. 2017). For example, a defendant may be convicted of
attempting to sell cocaine even if he was really peddling sugar.
See W. LaFave, supra. Likewise, a defendant may be
convicted of pandering or soliciting child pornography even if
the disputed images do not depict an actual child. See
Williams, 553 U.S. at 300. In such cases, “impossibility of
completing the crime because the facts were not as the
defendant believed is not a defense.” Id. Rather, the
defendant’s state of mind should be assessed “according to the
circumstances as he believes them to be, rather than the
circumstances as they may have existed in fact.” Id. (quoting
Model Penal Code § 5.01, cmt. 3, at 307 (1985)). This case
does not involve a typical inchoate crime, but the same
principle applies to construing the state-of-mind element of the
governing statute.

    Our analysis also tracks the views of our sister circuits.
Three courts of appeals have held that section 2423(b) applies
to a defendant who travels across state lines intending to
engage in sexual conduct with a child who, as things turn out,
does not exist. See United States v. Tykarsky, 446 F.3d 458,
469 (3d Cir. 2006) (“It makes no difference that an actual minor
                               8
was not involved.”) (cleaned up)); United States v. Sims, 428
F.3d 945, 959 (10th Cir. 2005) (rejecting defendant’s argument
that “because Kate does not exist, he could not be convicted”);
United States v. Root, 296 F.3d 1222, 1231 (11th Cir. 2002)
(“Root’s conviction turns simply on the illegal purpose for
which Root traveled.”). Likewise, five courts of appeals have
held that a defendant may be convicted of violating 18 U.S.C.
§ 2422(b), which prohibits attempting to persuade a minor to
engage in illicit sexual activity, even if no actual minor was
involved. See Tykarsky, 446 F.3d at 465–69; Sims, 428 F.3d at
959–60; United States v. Meek, 366 F.3d 705, 717–20 (9th Cir.
2004); Root, 296 F.3d at 1227–31; United States v. Farner, 251
F.3d 510, 512–13 (5th Cir. 2001). Lieu cites no contrary
authority, and we have not found any.

      We hold that a defendant violates section 2423(b) by
traveling in interstate commerce with the intent to engage in
illicit sexual conduct with a child, even if the defendant is
mistaken in believing that an actual child is involved. The
district court thus properly denied Lieu’s motion to dismiss the
charged travel offense.

                              III

     Lieu further contends that the district court abused its
discretion in admitting E.’s testimony. This claim involves the
interplay among three Federal Rules of Evidence. Rule 404(b)
provides that evidence of uncharged acts “is not admissible to
prove a person’s character in order to show that on a particular
occasion the person acted in accordance with the character,”
but that such evidence “may be admissible for another purpose,
such as proving motive, opportunity, intent, preparation, plan,
knowledge, identity, absence of mistake, or lack of accident.”
Rule 414(a) provides that in a criminal case where the
defendant is accused of “child molestation,” the district court
                                  9
“may admit evidence that the defendant committed any other
child molestation,” and this evidence “may be considered on
any matter to which it is relevant.” Rule 403 provides that the
district court “may exclude relevant evidence if its probative
value is substantially outweighed by a danger of,” among other
things, “unfair prejudice” or “confusing the issues.”

     The district court addressed each of these rules. Under
Rule 404(b), it held that E.’s testimony was admissible on
“issues of knowledge, intent, motive, and absence of mistake,”
to show that Lieu knowingly distributed child pornography and
traveled with an intent to engage in sexual conduct with a
minor. See Lieu, 298 F. Supp. 3d at 55. Under Rule 414(a),
the court further held that because the distribution offense
involved a crime of child molestation, Lieu’s prior abuse of E.,
which likewise involved child molestation, was also admissible
to show that Lieu had a propensity to distribute child
pornography. See id. at 57–59.2 On appeal, Lieu contests
neither ruling. Yet he contends that the court abused its
discretion in concluding under Rule 403 that E.’s testimony
was not substantially more prejudicial than probative.

    At the outset, we note two obvious difficulties with Lieu’s
position. First, Rule 403 establishes a high barrier to justify the
exclusion of relevant evidence, by requiring that its probative
value must be “substantially” outweighed by considerations
such as “unfair” prejudice. See United States v. Cassell, 292

     2
         Rule 414 defines “child molestation” to include any crime
“involving” specified kinds of contact between the defendant and the
child or “any conduct prohibited by 18 U.S.C. chapter 110.” Fed. R.
Evid. 414(d)(2). The offense of distributing child pornography, 18
U.S.C. § 2252(a)(2), is codified in chapter 110. The travel offense
in this case, 18 U.S.C. § 2423(b), is codified in chapter 117, and the
government does not contend that it otherwise qualifies as a crime of
child molestation under Rule 414.
                               10
F.3d 788, 796 (D.C. Cir. 2002). Second, our standard of review
is highly deferential: Because “the district court is in the best
position to conduct the balancing test,” United States v.
Whitmore, 359 F.3d 609, 619 (D.C. Cir. 2004), we review a
decision to admit evidence under Rule 403 “with great
deference, reversing only for grave abuse of discretion,” United
States v. Vega, 826 F.3d 514, 543 (D.C. Cir. 2016) (quotation
marks omitted). We find no grave abuse here.

     The district court reasonably concluded that E.’s testimony
had “significant” probative value. 298 F. Supp. 3d at 55. As
the court explained, the testimony showed that Lieu had a
“specific sexual interest in female children of approximately
[the same] age” as both Palchak’s purported daughter and the
girls in the pornographic images that Lieu sent to Palchak. Id.
This tended to show both that Lieu knowingly distributed child
pornography and that he traveled with the intent to engage in
sexual conduct with a minor. Moreover, this case turned
entirely on Lieu’s state of mind. It was clear that Lieu’s
cellphone sent images of child pornography to Palchak, but
Lieu disclaimed knowledge and stated that “mistakes could be
made even by computers.” S.A. 373. Likewise, it was clear
that Lieu traveled across state lines to meet Palchak, after
agreeing to engage in sexual conduct with his ostensible nine-
year-old. But Lieu disclaimed any bad intent, offering the
alternative explanation that he was seeking either to ferret out
possible wrongdoing or to recruit Palchak to sell insurance.
Indeed, Lieu even tendered an innocent explanation for his
extensive collection of child pornography—that another
computer error caused it to be downloaded. The prosecution
thus turned squarely on Lieu’s state of mind, and E.’s testimony
was directly relevant to it.

    The district court also reasonably concluded that any
unfair prejudice to Lieu would be “minimal.” 298 F. Supp. 3d
                               11
at 55. As the court explained, the abuse of E. was certainly
“abhorrent,” but her testimony would neither “dominate the
trial” nor be “especially graphic in the context of the crimes”
for which Lieu had been charged. Id. at 55–56. Indeed, the
touching described by E. pales in comparison to the sex acts
that Lieu planned to engage in with John’s daughter—
including everything up to but not including intercourse.
Likewise, E.’s account pales in comparison to the accounts that
Lieu himself provided to Palchak and the third party, which
included graphic descriptions of how much Lieu enjoyed the
encounters and wished they had gone further. A jury that heard
the latter would not likely be inflamed unfairly by the former.
See, e.g., United States v. Long, 328 F.3d 655, 668 (D.C. Cir.
2003); United States v. Anderson, 851 F.2d 384, 393–94 (D.C.
Cir. 1988). Finally, the district court gave appropriate limiting
instructions explaining the permissible and impermissible uses
of E.’s testimony.

     Lieu’s responses are unpersuasive. First, Lieu claims that
his abuse of E. was too dissimilar from the charged conduct to
have much probative value. But “the admissible bad acts
evidence need not show incidents identical to the events
charged, so long as they are closely related to the offense” and
“are probative of intent.” Long, 328 F.3d at 661 (quotation
marks omitted). Here, the district court reasonably concluded
that Lieu’s molesting his own stepdaughter, when she was
between ages six and eight, bore substantially on whether he
traveled to D.C. with an intent to molest a nine-year-old. See
United States v. Sebolt, 460 F.3d 910, 917 (7th Cir. 2006)
(“Prior instances of sexual misconduct with a child victim may
establish a defendant’s sexual interest in children and thereby
serve as evidence of the defendant’s motive to commit a
charged offense involving the sexual exploitation of
children.”). Likewise, the district court reasonably concluded
that testimony confirming Lieu’s sexual interest in young girls
                              12
bore on whether Lieu knowingly distributed pornographic
images of young girls. On the distribution count, Lieu objects
that he never contested knowledge about “the sexually explicit
nature of the material” or “the age of the performers,” United
States v. X-Citement Video, Inc., 513 U.S. 64, 78 (1994). But
Lieu did disclaim knowledge of how his cellphone transmitted
the three pornographic images to Palchak, even while
admitting to having transmitted tamer images of naked young
girls. Lieu’s demonstrated sexual interest in children bears on
this disputed knowledge issue.

     Next, Lieu contends that the abuse of E., which occurred
six to eight years before Lieu’s encounter with Palchak,
happened too long ago to be very probative. But in the context
of sex offenses, courts have admitted evidence of much older
conduct to show that the defendant acted with the requisite
intent. See, e.g., United States v. Underwood, 859 F.3d 386,
393 (6th Cir. 2017) (acts from 24 years before trial); United
States v. LeMay, 260 F.3d 1018, 1029 (9th Cir. 2001) (11
years); United States v. Gabe, 237 F.3d 954, 960 (8th Cir.
2001) (20 years). Moreover, Lieu himself confirmed the
significance of his encounters with E. by raising them in
salacious discussions with Palchak and the third party. See 298
F. Supp. 3d at 55. Lieu further suggests that the district court
misapprehended the relevant timeframes in stating that E.’s
abuse had occurred “within approximately four years” of the
charged conduct. See id. To the contrary, the court correctly
understood the chronology, and its reference to “four years”
denoted the last act of arguable abuse, involving the shower
incident that occurred when E. was about ten years old, rather
than the touching that occurred when she was between six and
eight. See id. at 42–43.

     On the prejudice side of the balance, Lieu contends that
the district court overlooked a risk that the jury would draw a
                                 13
forbidden propensity inference as to the travel offense. But that
possibility is present whenever a court admits evidence for a
limited purpose. See, e.g., United States v. Crowder, 141 F.3d
1202, 1210 (D.C. Cir. 1998) (en banc). Moreover, the risk of
an impermissible inference was not unusually high in this case.
There were only two charged offenses in a factually simple
case turning on whether Lieu knowingly distributed child
pornography on February 3 and traveled on February 4 with the
intent to engage in sexual activity with a minor. Finally, the
district court minimized the risk of an improper propensity
inference through jury instructions carefully setting forth the
permissible and impermissible uses of E.’s testimony. Such
limiting instructions “ordinarily suffice to protect the
defendant’s interests” regarding uncharged acts admitted for
limited purposes. See Long, 328 F.3d at 662. Lieu complains
that the district court gave the instructions at the end of his trial,
rather than when E.’s testimony was introduced. But Lieu did
not ask for limiting instructions at that time, so he forfeited any
objection to their timing. See United States v. Brawner, 32
F.3d 602, 605 (D.C. Cir. 1994). And Lieu has not attempted to
show that the district court committed plain error by giving the
instructions only at the end of trial. See Fed. R. Crim. P. 52(b);
United States v. Olano, 507 U.S. 725, 734 (1993). In any event,
as Lieu himself acknowledges, this Court has never held that a
limiting instruction must be given more than once. See United
States v. Winstead, 890 F.3d 1082, 1085 (D.C. Cir. 2018).

    For these reasons, we hold that the district court did not
abuse its discretion in admitting E.’s testimony.

                                                           Affirmed.
