The Federal Public Defender appointed to represent Jesus Israel Guardado has moved for leave to withdraw and has filed a brief and a supplemental brief in accordance with Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967), and United States v. Flores, 632 F.3d 229 (5th Cir. 2011). Guardado has filed responses to the original brief and to the supplemental brief. We have reviewed counsel’s briefs and the relevant portions of the record reflected therein, as well as Guardado’s responses. We concur with counsel’s assessment that this appeal presents no nonfrivolous issue for appellate review. Although Guardado urges this court to consider whether his attorney provided effective assistance of counsel under the Sixth Amendment, we conclude that the record is insufficiently developed on the pertinent issues, and we therefore decline to consider the matter. See United States v. Isgar, 739 F.3d 829, 841 (5th Cir. 2014). Guardado may assert ineffective-assistance-of-counsel claims in a habe-as corpus motion under 28 U.S.C. § 2255. 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.