The attorney appointed to represent Gerardo Rafael Perez has moved for leave to withdraw and has filed a brief in accordance with Anders v. California, 886 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967). Perez has filed a response. The record is insufficiently developed to allow consideration at this time of Perez’s claims of ineffective assistance of counsel; such claims generally “cannot be resolved on *524 direct appeal when [they have] not been raised before the district court since no opportunity existed to develop the record on the merits of the allegations.” United States v. Cantwell, 470 F.3d 1087, 1091 (5th Cir. 2006) (internal quotation marks and citation omitted). Our independent review of the record, counsel’s brief, and Perez’s response discloses no nonfrivolous issue for appeal. Accordingly, the motion for leave to withdraw is GRANTED, counsel is excused from further responsibilities herein, and the APPEAL IS DISMISSED. See 5th Cir. R. 42.2. Perez’s motion for the appointment of substitute counsel is DENIED. Cf. United States v. Wagner, 158 F.3d 901, 902-03 (5th Cir. 1998).