                          UNPUBLISHED

UNITED STATES COURT OF APPEALS
                FOR THE FOURTH CIRCUIT


UNITED STATES OF AMERICA,              
                 Plaintiff-Appellee,
                 v.                               No. 02-4253
WALTER ALBERTO MONTES,
             Defendant-Appellant.
                                       
           Appeal from the United States District Court
            for the District of Maryland, at Greenbelt.
                 Peter J. Messitte, District Judge.
                         (CR-00-199-PJM)

                  Submitted: February 11, 2003

                      Decided: February 27, 2003

         Before LUTTIG and MOTZ, Circuit Judges, and
               HAMILTON, Senior Circuit Judge.



Affirmed by unpublished per curiam opinion.


                             COUNSEL

Robert C. Bonsib, Beau Kealy, MARCUS & BONSIB, Greenbelt,
Maryland, for Appellant. Thomas M. DiBiagio, United States Attor-
ney, James M. Trusty, Assistant United States Attorney, Greenbelt,
Maryland, for Appellee.
2                      UNITED STATES v. MONTES
Unpublished opinions are not binding precedent in this circuit. See
Local Rule 36(c).


                               OPINION

PER CURIAM:

   Walter Alberto Montes appeals his conviction on thirteen counts of
preparing or assisting the preparation and presentation of fraudulent
tax returns, in violation of 26 U.S.C. § 7206(2) and 18 U.S.C. § 2
(2000), and one count of making and presenting a false claim against
the United States, in violation of 18 U.S.C. §§ 287, 2 (2000). Finding
no reversible error, we affirm.

   On appeal, Montes first asserts that the district court erred in per-
mitting an IRS agent to testify regarding certain aspects of the prepa-
ration of income tax returns and the prerequisites for certain
exemptions and credits on the returns. We review a district court’s
decisions on the admissibility of evidence for an abuse of discretion.
See United States v. Moore, 27 F.3d 969, 974 (4th Cir. 1994). The
district court will not be found to have abused its discretion unless it
acted "arbitrarily or irrationally." Id. Our review of the agent’s testi-
mony convinces us that the district court properly limited the testi-
mony and did not abuse its discretion in allowing the testimony as so
limited.

   Montes next asserts that the district court erred in denying his
motion for a mistrial due to improper comments by the prosecutor
during rebuttal closing argument. We review a district court’s denial
of a motion for a mistrial for an abuse of discretion. See United States
v. Dorlouis, 107 F.3d 248, 257 (4th Cir. 1997). Montes asserts that
the prosecutor’s comments were improper attempts to focus the jury
on the fact that he did not testify at trial or otherwise offer any evi-
dence, and that the district court’s curative instruction was insufficient
to overcome the taint of the improper comments.
  A prosecutor’s improper closing argument may "so infect[] the trial
with unfairness as to make the resulting conviction a denial of due
process." United States v. Wilson, 135 F.3d 291, 297 (4th Cir. 1998)
                        UNITED STATES v. MONTES                          3
(quoting Darden v. Wainwright, 477 U.S. 168, 181 (1986)) (internal
quotation marks omitted). In determining whether a defendant’s due
process rights were violated by a prosecutor’s closing argument, this
court considers whether the remarks were, in fact, improper, and, if
so, whether the improper remarks "so prejudiced the defendant’s sub-
stantial rights that the defendant was denied a fair trial." Id. We con-
clude that the prosecutor’s comments in this case were not improper
because the comments were "merely ‘a fair response to a claim made
by defendant or his counsel.’" Howard v. Moore, 131 F.3d 399, 421
(4th Cir. 1997) (en banc) (quoting United States v. Robinson, 485
U.S. 25, 32 (1988)). Moreover, even if the remarks were improper,
under the six-factor test articulated in Wilson, the comments were not
so prejudicial as to deny Montes a fair trial, particularly in light of the
district court’s contemporaneous curative instruction to the jury. Wil-
son, 135 F.3d at 299.
   Montes next argues that the district court erred in denying his
request that the jury be instructed on the definition of reasonable
doubt. This court has held that "it is improper for a district court to
define reasonable doubt for a jury unless the jury itself requests a def-
inition." United States v. Najjar, 300 F.3d 466, 486 (4th Cir.), cert.
denied, ___ U.S. ___, 123 S. Ct. 705 (2002). Montes acknowledges
the rule in this circuit, but suggests that this precedent be reconsid-
ered. Because a panel of this court may not overrule a prior published
decision of the court, Montes’ assertion of error is baseless. See
United States v. Ruhe, 191 F.3d 376, 388 (4th Cir. 1999).
   Montes’ final argument is that the district court erred in refusing
to give instructions he proffered on good faith and willfulness. We
have considered the requested instructions and conclude that the dis-
trict court did not commit reversible error in refusing these instruc-
tions because they were fairly covered by the court’s instructions. See
United States v. Lewis, 53 F.3d 29, 32 (4th Cir. 1995) (quoting United
States v. Camejo, 929 F.2d 610, 614 (11th Cir. 1991)).
   We affirm Montes’ convictions and sentence. We dispense with
oral argument because the facts and legal contentions are adequately
presented in the materials before the court and argument would not
aid the decisional process.
                                                             AFFIRMED
