United States Court of Appeals
                            FOR THE EIGHTH CIRCUIT
                                    ___________

                                    No. 01-1292
                                    ___________

United States of America,           *
                                    *
            Appellee,               *
                                    * Appeal from the United States
      v.                            * District Court for the
                                    * Northern District of Iowa.
Ismael Guzman-Fregoso, also known *
as Chi-Chi,                         *       [UNPUBLISHED]
                                    *
            Appellant.              *
                               ___________

                          Submitted: November 7, 2001
                              Filed: November 16, 2001
                                   ___________

Before BOWMAN, LOKEN, and MORRIS SHEPPARD ARNOLD, Circuit Judges.
                          ___________

PER CURIAM.

       After Ismael Guzman-Fregoso pleaded guilty to conspiracy to distribute
methamphetamine, in violation of 21 U.S.C. §§ 841(a)(1), 841(b)(1)(A)(viii), and
846, the district court1 sentenced him to 270 months in prison and 5 years supervised
release. On appeal, counsel moved to withdraw under Anders v. California, 

(1967), and filed a brief arguing that the United States breached a promise to file
a motion for downward departure for substantial assistance. Guzman-Fregoso filed

      1
       The HONORABLE MARK W. BENNETT, Chief Judge, United States
District Court for the Northern District of Iowa.
a pro se supplemental brief arguing that his plea was unknowing and involuntary
because he was induced to plead guilty by the government’s promise to make such
a motion, and that his counsel was ineffective. We reject these arguments and affirm.

      The plea agreement clearly preserved the government’s discretion to determine
whether Guzman-Fregoso provided substantial assistance, see United States v.
Romsey, 

, 558 (8th Cir. 1992), and he did not attempt to show the
government’s refusal was made in bad faith, was irrational, or was based on an
unconstitutional motive, see Wade v. United States, 

, 185-86 (1992). In
addition, Guzman-Fregoso gave assurances under oath at his plea hearing that he
understood the government had discretion in determining whether to make a
departure motion. His failure to attempt to withdraw his guilty plea precludes him
from challenging its voluntariness on appeal. See United States v. Murphy, 

, 716 (8th Cir. 1990). Guzman-Fregoso’s ineffective-assistance claims are more
appropriately presented in a 28 U.S.C. § 2255 proceeding. See United States v.
Martin, 

, 771 (8th Cir. 1995).

       Finally, following our independent review in accordance with Penson v. Ohio,

(1988), we find no nonfrivolous issues. Accordingly, we affirm and
grant counsel’s motion to withdraw.

      A true copy.

             Attest:

                     CLERK, U. S. COURT OF APPEALS, EIGHTH CIRCUIT.




                                         -2-