OPINION

Alexander O’Brian Williams pled guilty pursuant to a written plea agreement to two counts of distribution of crack cocaine, in violation of 21 U.S.C. § 841(a) (2000). Williams was sentenced to 223 months imprisonment on each count, to run concurrently. In these consolidated appeals, Williams challenges the district court’s denial of his motions to withdraw his guilty plea and to appoint an expert voice identification witness. Williams has also filed a supplemental pro se brief in which he claims that his due process rights were violated. We affirm.

*716 We review the denial of a motion to withdraw a guilty plea for abuse of discretion. United States v. Ubakanma, 215 F.3d 421, 424 (4th Cir. 2000). Williams must present a “fair and just” reason for withdrawing his guilty plea. Fed.R.Crim.P. 32(e); United States v. Moore, 931 F.2d 245, 248 (4th Cir. 1991). Based on the factors set forth in Moore, we find the district court did not abuse its discretion in denying the motion to withdraw his guilty plea.

Next, Williams challenges the district court’s denial of his motion to appoint a voice identification expert to examine the tape recording of the transaction underlying count 2 of the indictment. To show reversible error in a district court’s refusal to appoint an expert pursuant to 18 U.S.C. § 3006A(e) (2000), Williams must demonstrate that the court’s refusal was prejudicial to his defense. United States v. Perrera, 842 F.2d 73, 77 (4th Cir. 1988). In light of his valid guilty plea, we find that Williams cannot establish that the denial of his motion was prejudicial to his defense.

Finally, Williams alleges that referral of his case for federal rather than state prosecution violated his due process rights. This claim, however, is meritless. United States v. Carter, 953 F.2d 1449, 1461-62 (5th Cir. 1992).

Accordingly, we grant Williams’ motion to file a supplemental pro se brief and affirm his conviction. 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.