United States Court of Appeals
                            FOR THE EIGHTH CIRCUIT
                                     ___________

                                     No. 08-1247
                                     ___________

United States of America,                *
                                         *
             Appellee,                   *
                                         * Appeal from the United States
      v.                                 * District Court for the
                                         * Western District of Missouri.
Don L. Elbert, II,                       *
                                         *
             Appellant.                  *
                                     __________

                              Submitted: October 16, 2008
                                 Filed: April 6, 2009
                                  ___________

Before RILEY, BOWMAN, and COLLOTON, Circuit Judges.
                           ___________

RILEY, Circuit Judge.

       Don L. Elbert, II (Elbert) pled guilty, pursuant to a plea agreement, to one count
of sex trafficking of a child in violation of 18 U.S.C. § 1591. Elbert reserved his right
to appeal the district court’s1 denial of his three pretrial motions to admit evidence of
the victims’ alleged sexual behavior. Elbert now appeals, claiming the district court’s
exclusion of evidence the victims allegedly engaged in other acts of prostitution
before and after the charged offenses violated his Fifth Amendment right to due



      1
       The Honorable Ortrie D. Smith, United States District Judge for the Western
District of Missouri.
process and his Sixth Amendment right to confront the witnesses against him. We
affirm.

I.     BACKGROUND
       On June 21, 2006, an undercover detective with the Kansas City (Missouri)
Police Department was participating in a prostitution sting when he observed two
females waving down cars and walking back and forth on the sidewalk. The
undercover detective drove his vehicle to the area and initiated a conversation with
one of the females. During this conversation, they agreed that the female would
provide oral sex to the undercover detective in exchange for twenty dollars. The
undercover detective signaled other members of the Police Department, and a
uniformed officer stopped the undercover detective’s vehicle. The female was
immediately placed under arrest. Meanwhile, another detective observed two other
females in the area watching the arrest. When these females saw what was taking
place, they began to run toward a Chevrolet Suburban. The driver of the Suburban
picked the two females up, but was stopped after driving a short distance. The driver,
identified as Elbert, was arrested for promoting prostitution.

        After Elbert’s arrest, the three females were transported to police headquarters
where they were each interviewed separately. Upon questioning, the police
determined the females were actually young girls and sisters. The oldest sister was
fifteen years old while the two younger sisters were thirteen year-old twins. Each child
independently told the officers they worked as prostitutes to provide money to Elbert.
The children explained that, on a nightly basis, Elbert transported all three girls to the
area where the police observed them soliciting prostitution. Elbert instructed the
children to work as prostitutes on separate street corners while Elbert monitored them.
Each child was expected to earn sixty dollars a night, and they were often not
permitted to leave the streets until they made fifty to one hundred dollars. Elbert took
all of the money the children earned as prostitutes in exchange for food, clothing, and
housing.

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      On June 30, 2006, each child was interviewed by a Child Protective Services
(CPS) investigator. The children separately explained they met Elbert when he
stopped his vehicle and began to speak with the oldest child, while they were all
standing outside a liquor store in Kansas City, Missouri. Elbert exchanged telephone
numbers with the oldest child and, during their conversations, she explained the girls
were unhappy with their home situation and had considered leaving home. One night,
Elbert picked up all three children from their home. That same night, the children
attended a party where two of them engaged in sex acts. The three girls returned
home. A week later, Elbert picked up the children, but this time, they did not return
home.

        During their interviews with the CPS investigator, the children detailed their
stay with Elbert. Elbert had sexual relations with each of the children “to see how
good they were before he put them out on the streets to work as prostitutes.” Elbert
took pictures of the children while they were showering, showed them pornographic
movies, and often threatened them. Elbert told the children they were being watched
at all times and warned them not to call anyone. The girls were afraid to leave or
contact anyone because Elbert often became angry and violent.

       On June 22, 2006, a criminal complaint was filed in the Western District of
Missouri, charging Elbert with sex trafficking of a child between May 1, 2006, and
June 20, 2006, in violation of 28 U.S.C. § 1591. A superseding indictment was
subsequently filed adding two additional charges of the same offense. During the
course of his proceedings, Elbert filed a motion, pursuant to Fed. R. Evid.
412(c)(1)(A), to admit evidence of the victims’ previous and subsequent sexual
behavior. The district court denied Elbert’s motion because it was not timely filed,
and explained the court would not have granted the motion even if it were timely filed
because the evidence did not qualify for admission under one of the exceptions to Fed.
R. Evid. 412 and was not relevant. The trial was continued for unrelated reasons, and
Elbert filed a timely motion asking the court to reconsider his earlier motion to admit

                                         -3-
evidence of the victims’ prior sexual behavior, arguing relevance as well as
confrontation and due process constitutional implications. Once again, the district
court denied the motion, finding the evidence irrelevant and any impeachment value
“of such limited value” so as not to implicate Elbert’s constitutional rights. In
response, Elbert filed a third motion asking the court to reconsider its previous rulings,
and additionally claiming the preclusion of evidence of the victims’ sexual history
denied him the right to present a complete defense. Shortly thereafter, the district
court denied Elbert’s third motion.

       On May 14, 2007, Elbert pled guilty to one count of sex trafficking of a child.
In accord with the terms of his plea agreement, Elbert was sentenced to eight years
imprisonment, the remaining counts of his indictment were dismissed, and Elbert
retained the right to appeal the district court’s rulings on his previous motions seeking
to admit evidence of the victims’ sexual history. This appeal followed.

II.    DISCUSSION
       A.     Standard of Review
       “We review the evidentiary rulings of a district court only for abuses of
discretion, and will reverse only when an improper evidentiary ruling affects the
substantial rights of the defendant or when we believe that the error has had more than
a slight influence on the verdict.” United States v. Ballew, 

, 941 (8th Cir.
1994) (citations omitted). “[E]rror may not be predicated upon a ruling excluding
evidence unless a substantial right of the party is affected and ‘the substance of the
evidence was made known to the court by offer’ or was apparent from the context of
the questions.” Lee v. Rapid City Area School Dist. No. 51-4, 

, 321 (8th
Cir. 1992) (quoting Fed. R. Evid. 103(a)(2)).

      The government urges us to find Elbert did not sufficiently preserve his issues
for appeal because he did not make a sufficient offer of proof to the district court.
“When a party has failed to preserve an evidentiary issue for appellate review,” we

                                           -4-
review for plain error. Williams v. Wal-Mart Stores, Inc., 

, 1360 (8th
Cir. 1990) (citation omitted). “The purpose of an offer of proof is to inform the court
and opposing counsel of the substance of the excluded evidence and to provide the
appellate court with a record sufficient to allow it to determine if the exclusion was
erroneous.” Ulmer v. Associated Dry Goods Corp., 

, 1283 n.2 (8th Cir.
1987) (citation omitted).

      While it is debatable whether Elbert’s alleged evidence actually exists, Elbert
submitted a motion to the court asking the court’s permission to admit the following
evidence:

      (1) Statements of the alleged victims made to agents of the Federal
      Bureau of Investigation indicating that they had prostituted themselves
      before they were acquainted with the defendant; and (2) Medical records
      and statements of the alleged victims made to officers of the Kansas
      City, Missouri, Police Department indicating that they had prostituted
      themselves after the defendant already had been arrested for the offenses
      with which he currently is charged and was in custody of law
      enforcement officers.

Although Elbert failed to point to any actual interview, medical record, or statement
where the victims supposedly admitted to other acts of prostitution, he did inform the
district court of the documents and subject matter of the evidence he wished to submit.
 However, we need not definitively decide the sufficiency of Elbert’s offer of proof
because, regardless of the standard of review, Elbert’s claim fails.

       B.     Excluded Evidence
       Elbert charges his constitutional rights were violated when he was not permitted
to introduce evidence his victims engaged in other acts of prostitution. It is true
defendants have a constitutional right to introduce evidence in their own defense. See
United States v. Bordeaux, 

, 558 (8th Cir. 2005). However, this “right
is not without limitation; it may sometimes have to ‘bow to accommodate other

                                         -5-
legitimate interests in the criminal trial process.’” 

States v.
Scheffer, 

, 308 (1998)). Such limitations, when placed upon a criminal
defendant’s right to present evidence, “may not be arbitrary or disproportionate to the
purposes they are designed to serve.” 

v. Lucas, 

,
151 (1991)). Our court has already held the limitations created by Fed. R. Evid. 412
on a defendant’s ability to present evidence “is not arbitrary or disproportionate to the
purpose it is designed to serve,” because the exclusion serves an important
interest—the prevention of “potential embarrassment or harassment of alleged victims
of sexual abuse.” 

      “Rule 412 excludes, in civil or criminal proceedings involving alleged sexual
misconduct, any evidence about a victim’s sexual behavior unless certain conditions
are met.” Wilson v. City of Des Moines, 

, 642 (8th Cir. 2006). One of
the purposes of this rule is “‘to safeguard the alleged victim against the invasion of
privacy, potential embarrassment and sexual stereotyping that is associated with
public disclosure of intimate sexual details.’” 

(quoting Fed. R. Evid. 412
Advisory Committee Notes). In a criminal case, evidence of a victim’s sexual
behavior is only admissible for three purposes: (1) to prove a person other than the
accused was the source of semen, injury or other physical evidence; (2) to show the
victim consented to sexual activity with the accused; and (3) to avoid a violation of
the defendant’s constitutional rights. Fed. R. Evid. 412(b)(1).

       None of the exceptions to the general rule of exclusion are applicable here. The
first exception is not applicable because the government never attempted to prove
Elbert caused any physical injury to the children or that he left behind semen or other
physical evidence. See Fed. R. Evid. 412(b)(1)(A). Elbert was charged with sex
trafficking of the minor children, not assault, abuse, or some other injury crime.
Similarly, the second exception is inapplicable because Elbert was not charged with
having sexual contact with the children, and further, the minor children could not
consent to sexual contact. See Fed. R. Evid. 412(b)(1)(B); see also United States v.

                                          -6-
Abad, 

, 797 (8th Cir. 2003) (“‘[W]hen sexual assaults are committed
upon children . . . , consent is not a defense.”’ (quoting Guarro v. United States, 

, 581 (D.C. Cir. 1956))). The final exception permits admission of “evidence
the exclusion of which would violate the constitutional rights of the defendant.” Fed.
R. Evid. 412(b)(1)(C).

       Elbert first contends he was deprived of his Fifth Amendment due process right
to present a “far more powerful defense” when he was not permitted to admit evidence
of the child-victims’ sexual behavior. Specifically, Elbert argues he could not
“effectively defend himself regarding allegations that he enticed and recruited the
alleged victims in this case, and caused them to engage in commercial sex acts.”2

      What Elbert fails to recognize is the evidence he wishes to admit does not
provide a defense for the crime with which he was charged and convicted. Elbert
repeatedly argues evidence of the victims’ prior acts of prostitution demonstrates he
did not cause them to engage in commercial sex acts. This argument relies upon an
improper construction of the phrase “caused to engage.” 18 U.S.C. § 1591(a).


      2
      Elbert was charged with sex trafficking of a child under 18 U.S.C. § 1591(a),
which states:

      Whoever knowingly–

         (1) in or affecting interstate or foreign commerce . . . recruits,
         entices, harbors, transports, provides, or obtains by any means a
         person; or
         (2) benefits, financially or by receiving anything of value, from
         participation in a venture which has engaged in an act described in
         violation of paragraph (1),
      knowing . . . the person has not attained the age of 18 years and will be
      caused to engage in a commercial sex act, shall be punished as provided
      in subsection (b).


                                         -7-
Because the victims were minors and could not legally consent, the government did
not need to prove the elements of fraud, force, or coercion, which are required for
adult victims. 

government was only required to prove Elbert
knowingly recruited, enticed, harbored, transported, provided, or obtained a minor,
knowing the minor would be caused to engage in commercial sex acts. 

children engaged in acts of prostitution before or after their encounters with Elbert
is irrelevant, and would only prove other people may be guilty of similar offenses of
recruiting, enticing, or causing these victims to engage in a commercial sex act. The
disputed evidence did not go to any element of the offense for which Elbert was
charged, and the exclusion of such irrelevant evidence did not violate the Due Process
Clause of the Fifth Amendment.

       Second, the excluded evidence did not violate Elbert’s Sixth Amendment right
to confrontation. The Confrontation Clause only requires admission of probative
evidence. See United States v. White Buffalo, 

, 1054 (8th Cir. 1996).
If evidence has only minimal probative value and would have a highly prejudicial
effect, a court can exclude the evidence without infringing upon the Confrontation
Clause or other constitutional rights of a defendant. See id.; United States v. Bartlett,

, 1088-89 (8th Cir. 1988).

       Elbert maintains the district court violated his right to confront the witnesses
against him when he was not permitted to impeach the victim-witnesses about other
alleged acts of prostitution. In the past, our court has declared, “unchastity of a
victim has no relevance whatsoever to [the victim’s] credibility as a witness.” United
States v. Kasto, 

, 271-72 n.3 (8th Cir. 1978). Such evidence also has no
impeachment value here because evidence the children previously engaged in
prostitution does not contradict evidence the children engaged in the acts of
prostitution for which Elbert has been charged. Assuming any impeachment
relevance of the minors engaging in other acts of prostitution, any probative value the
evidence may have “is substantially outweighed by the danger of unfair prejudice.”

                                          -8-
See Fed. R. Evid. 403. See also 

(“In light of the minimal
probative value of the evidence and the important purpose of the exclusion, then,
exclusion of the statement was not disproportionate to the purpose behind the
exclusion.”). The district court’s exclusion of the evidence did not violate the
Confrontation Clause, and the district court did not abuse its discretion when it
excluded Elbert’s evidence.

III.   CONCLUSION
       We affirm the judgment of the district court.
                       ______________________________




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