                           UNPUBLISHED

UNITED STATES COURT OF APPEALS
                FOR THE FOURTH CIRCUIT


UNITED STATES OF AMERICA,              
                 Plaintiff-Appellee,
                 v.                            No. 02-4233
RONALD E. WALKER,
             Defendant-Appellant.
                                       
            Appeal from the United States District Court
     for the Southern District of West Virginia, at Charleston.
             Charles H. Haden II, Chief District Judge.
                            (CR-01-103)

                  Submitted: September 4, 2002

                      Decided: September 23, 2002

Before NIEMEYER, WILLIAMS, and GREGORY, Circuit Judges.



Affirmed by unpublished per curiam opinion.


                              COUNSEL

E. Dixon Ericson, JOHN R. MITCHELL, L.C., Charleston, West Vir-
ginia, for Appellant. Kasey Warner, United States Attorney, Stepha-
nie L. Haines, Assistant United States Attorney, Charleston, West
Virginia, for Appellee.



Unpublished opinions are not binding precedent in this circuit. See
Local Rule 36(c).
2                       UNITED STATES v. WALKER
                                OPINION

PER CURIAM:

   Ronald E. Walker appeals his convictions and sentences on charges
of aiding and abetting a scheme involving mail and wire fraud and the
use of fire in committing a federal felony. Walker was convicted of
three separate fraudulent schemes. The first, which he does not chal-
lenge on appeal, involved tools and equipment that he falsely reported
stolen from his garage. The second concerned a truck belonging to
Charles D. Matthews, which Matthews falsely reported stolen to
obtain insurance money. The third fraud involved Walker’s and Mat-
thews’ trucks and a flatbed trailer that were purposely set on fire in
order to collect insurance proceeds. Walker was sentenced to thirty-
seven months for aiding and abetting mail and wire fraud and a con-
secutive term of one hundred twenty months for use of fire in the
commission of a federal felony.

                                     I.

   Walker first argues that the district court failed to instruct the jury
on the materiality element of mail and wire fraud. See United States
v. Neder, 527 U.S. 1, 25 (1999) ("Accordingly, we hold that material-
ity of falsehood is an element of the federal mail fraud, wire fraud,
and bank fraud statutes."). To prove the omission, Walker cites to a
portion of the district court’s instructions discussing the required rela-
tionship between the use of the mail and the fraudulent scheme and
the defendant’s personal involvement with the use of the mail. How-
ever, while that section of the instructions did not mention materiality,
the remainder of the instructions properly explained to the jury that
the Government was required to prove that the fraud concerned a
material matter. (See J.A. at 483-85 ("[T]he government would have
to prove to you . . . that the scheme . . . involved a plan . . . to deceive
another with regard to a material matter."), 486 ("The term false or
fraudulent pretenses . . . means a statement . . . which concerns a
material or important fact.").) The court also defined the term "mate-
rial fact." (J.A. at 486). Thus, because the jury instructions as a whole
were fair, adequate, and proper, there was no error. See Smith v. Univ.
of NC, 632 F.2d 316, 332 (4th Cir. 1980) (standard of review).
                      UNITED STATES v. WALKER                        3
                                  II.

   Walker challenges the district court’s limitation of his cross-
examination of two Government witnesses. First, he claims he should
have been permitted to question Lorrie Walker as to her involvement
with drug dealers while serving as a Government informant. Second,
he asserts that he should have been allowed to interrogate Matthews
regarding his avoidance through his plea agreement of a ten year
mandatory minimum sentence for use of fire in the commission of a
felony.

   A district court’s decision to limit cross-examination is reviewed
for abuse of discretion. United States v. Cropp, 127 F.3d 354, 358
(4th Cir. 1997). A defendant has a right under the Confrontation
Clause to cross-examine witnesses who are cooperating with the Gov-
ernment about potential sources of bias. Id. However, the trial court
retains the discretion to place reasonable limits on cross-examination
based on concerns about, among other things, harassment, prejudice,
confusion, repetition, or relevance. Delware v. Van Arsdall, 475 U.S.
673, 678-79 (1986). An improper denial of an opportunity to examine
a witness for bias is subject to harmless error review. Id. at 684.

   Regarding Lorrie Walker’s testimony, Walker asserted that his
cross-examination would have shown that Lorrie Walker was highly
motivated to provide information and trial testimony adverse to
Walker to avoid prosecution for her alleged involvement in drug deal-
ing. However, specific instances of unconvicted conduct are only
admissible to attack a witness’s credibility if they are probative of
truthfulness or untruthfulness. Fed. R. Evid. 608. Walker did not prof-
fer evidence that the Government was aware of the drug dealing and
purposely ignored it in order to obtain testimony against Walker. Fur-
ther, drug dealing is not the type of conduct that necessarily bears on
a witness’s character for truthfulness. See United States v. Leake, 642
F.2d 715, 718 (4th Cir. 1981) (stating that Rule 608(b) expressly per-
mits inquiry into instances of misconduct that are clearly probative of
truthfulness or untruthfulness, such as perjury, fraud, swindling, for-
gery, bribery, and embezzlement). Finally, Walker’s theory would gut
Rule 608(b), since every Government witness who has committed
uncharged criminal conduct has an interest in cooperating with the
Government to avoid prosecution or detection. Thus, because Rule
4                      UNITED STATES v. WALKER
608(b) prevents the admission of prior conduct except as it bears on
a propensity to tell the truth, the district court’s limitation was proper.

   Turning to the cross-examination of Matthews, the court refused to
allow questioning regarding the mandatory minimum sentence
because such questioning would, in effect, inform the jury as to the
sentence faced by Walker. The court did, however, permit generic
questioning as to whether Matthews had secured a favorable bargain
by assisting the Government. Because the district court’s limitation
was reasonable and because Walker was still able to cross-examine
Matthews regarding his favorable plea, we find that Walker was not
prejudiced by the court’s ruling.

                                   III.

   Walker next argues that the evidence was insufficient to show that
he aided and abetted Matthews in defrauding the insurance companies
regarding the "stolen" truck and the burned trucks. According to
Walker, the evidence only showed that he was aware of Matthews’
scheme, but failed to prove that he was involved. We review a jury
verdict for sufficiency of the evidence by determining whether there
is substantial evidence, when viewed in a light most favorable to the
Government, to support the verdict. Glasser v. United States, 315
U.S. 60, 80 (1942). In evaluating the sufficiency of the evidence, we
do not review the credibility of the witnesses, and we assume that the
jury resolved all contradictions in testimony in favor of the Govern-
ment. United States v. Romer, 148 F.3d 359, 364 (4th Cir. 1998).

   Regarding the "stolen" truck fraud, Dennie Leach and Matthews
testified that Walker initiated the idea, fronted the money for the new
truck, and stored Matthews’ "stolen" truck in his garage while Mat-
thews reported to his insurance company that it was stolen. Leach and
David King testified that they saw the Matthews’ disassembled truck
in Walker’s garage. Finally, Leach testified that Walker told him to
get rid of the truck pieces. The testimony, if believed, was more than
sufficient to show that Walker aided and abetted Matthews in
defrauding the insurance company.

   Concerning the truck fire fraud, Lorrie Walker and Matthews both
testified that Walker was involved in planning the burning of the
                       UNITED STATES v. WALKER                       5
trucks and choosing the method for setting the fire. Other witnesses
stated that Walker lied to the police about not having insurance on his
burned truck. Finally, Walker filed a claim on his truck and collected
the insurance proceeds. Again, if believed, this testimony was suffi-
cient to show that Walker aided and abetted a scheme to defraud.

                                  IV.

  Section 844(h) reads, in pertinent part:

      (a) Whoever -

          (1) uses fire or an explosive to commit any felony
          which may be prosecuted in a court of the United
          States, or

          (2) carries an explosive during the commission of
          any felony which may be prosecuted in a court of
          the United States, shall, in addition to the punish-
          ment provided for such felony, be sentenced to
          imprisonment for ten years . . . . Notwithstanding
          any other provision of law, the court shall not
          place on probation or suspend the sentence of any
          person convicted of a violation of this subsection,
          nor shall the term of imprisonment imposed under
          this subsection run concurrently with any other
          term of imprisonment including that imposed for
          the felony in which the explosive was used or car-
          ried.

Walker argues that the language barring the concurrent running of the
additional sentence with "any other term of imprisonment including
that imposed for the felony in which the explosive was used or car-
ried" (emphasis added), does not bar concurrent sentences as to
crimes, such as Walker’s, that involved fire rather than explosives.
However, we have already rejected Walker’s argument. United States
v. Ramey, 24 F.3d 602, 610 (4th Cir. 1994) ("Certainly [the statute’s]
language of inclusion cannot be tortured into an exclusion of sen-
tences for underlying fire-related felonies.").1 Thus, the court’s con-
  1
   Ramey was abrogated on other grounds by Jones v. United States, 529
U.S. 848 (2000).
6                       UNITED STATES v. WALKER
clusion that the ten year sentence under § 844(h) must run
consecutively to Walker’s other convictions was not error.2

                                    V.

   Finally, Walker contends that, because § 844(h)(1) does not contain
an interstate nexus, his conviction is invalid. However, § 844(h)(1)
does not facially exceed Congress’s commerce power, because it is
a generic penalty section that draws its constitutional authority from
the requirement that the underlying felonies—here, mail and wire
fraud—can be prosecuted "in a court of the United States." Because
Walker concedes that federal jurisdiction exists regarding his mail
and wire fraud convictions, there was no jurisdictional error in his
conviction. See United States v. Pappadopoulos, 64 F.3d 522, 528
(9th Cir. 1995).

   Accordingly, we affirm Walker’s convictions and sentences. We
dispense with oral argument, because the facts and legal contentions
are adequately presented in the materials before the court and argu-
ment would not aid the decisional process.

                                                              AFFIRMED
    2
   Walker also argues that the ten-year minimum mandatory penalty was
disproportionately severe in his case. However, we will not review a sen-
tence for proportionality if that sentence is less than life without parole.
United States v. Lockhart, 58 F.3d 86, 89 (4th Cir. 1995).
