Thomas H. Ostrander, appointed counsel for Roberto Trevino in this direct criminal appeal, has filed both a motion to withdraw from further representation of Mr. Trevino and a brief pursuant to Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967). Our independent re*873view of the entire record reveals that Mr. Ostrander’s assessment of the relative merit of Mr. Trevino’s appeal is correct. Having also reviewed Mr. Trevino’s response to the Anders brief filed by Mr. Ostrander, we conclude that (1) the appeal waiver bars Mr. Trevino’s argument concerning the district court’s leadership-role sentence enhancement and (2) any claims of ineffective assistance of counsel must be left to a proceeding pursuant to 28 U.S.C. § 2255 because of the undeveloped nature of the record. Because independent examination of the entire record reveals no arguable issues of merit, Mr. Ostrander’s motion to withdraw is GRANTED, and Mr. Trevino’s conviction and sentence are AFFIRMED.