                          UNPUBLISHED

UNITED STATES COURT OF APPEALS
                FOR THE FOURTH CIRCUIT


UNITED STATES OF AMERICA,              
                 Plaintiff-Appellee,
                 v.                              No. 00-4396
TOMMY ARTHUR MILLS,
            Defendant-Appellant.
                                       
            Appeal from the United States District Court
         for the District of South Carolina, at Spartanburg.
                Margaret B. Seymour, District Judge.
                             (CR-99-845)

                  Submitted: September 29, 2000

                      Decided: October 19, 2000

  Before NIEMEYER, LUTTIG, and TRAXLER, Circuit Judges.



Affirmed by unpublished per curiam opinion.


                             COUNSEL

C. Carlyle Steele, Jr., Greenville, South Carolina, for Appellant. J.
Rene Josey, United States Attorney, Isaac L. Johnson, Jr., Assistant
United States Attorney, Greenville, South Carolina, for Appellee.



Unpublished opinions are not binding precedent in this circuit. See
Local Rule 36(c).
2                       UNITED STATES v. MILLS

                              OPINION

PER CURIAM:

   Tommy Arthur Mills pled guilty to possession of crack cocaine
with intent to distribute, see 21 U.S.C.A. § 841(a) (West 1999), and
was sentenced to a term of 210 months imprisonment and five years
supervised release. On appeal, he challenges the district court’s deci-
sion to deny him an adjustment for acceptance of responsibility, see
U.S. Sentencing Guidelines Manual § 3E1.1 (1998), and its refusal to
compel the government to move for a substantial assistance departure
under USSG § 5K1.1, p.s. We affirm.1

   Mills entered a guilty plea to possession of crack with intent to dis-
tribute after he participated in a sale of 115 grams of crack. The pro-
bation officer recommended against an adjustment for acceptance of
responsibility because Mills denied being involved in the drug sale for
which he was arrested. Mills claimed that the probation officer had
simply misconstrued one of Mills’ statements, and, moreover, had lost
his temper and ended the interview prematurely. Accepting the proba-
tion officer’s version of events, the district court found that Mills had
not accepted responsibility. The district court’s determination that a
defendant has not accepted responsibility is reviewed for clear error.
See United States v. Randall, 171 F.3d 195, 210 (4th Cir. 1999). The
defendant has the burden of showing by a preponderance of the evi-
dence that he is entitled to the adjustment, and entry of a guilty plea
is not in itself sufficient. See United States v. Nale, 101 F.3d 1000,
1005 (4th Cir. 1996). Mills argues that the district court clearly erred
in accepting the probation officer’s testimony concerning the presen-
tence interview and discounting his contrary account. The issue is
thus one of credibility, and the district court’s determination that the
probation officer was the more credible witness is not reviewable on
appeal. See United States v. Hobbs, 136 F.3d 384, 390-91 n.11 (4th
Cir. 1998). Given that the district court accepted the probation offi-
    1
   We have considered the effect of Apprendi v. New Jersey, 120 S. Ct.
2348 (2000), and find that, because Mills received a sentence of impris-
onment that did not exceed the statutory maximum set out in 21 U.S.C.A.
§ 841(b)(1)(C) (West 1999), no plain error occurred. See United States
v. Aguayo-Delgado, 220 F.3d 926, 933-34 (8th Cir. 2000).
                        UNITED STATES v. MILLS                          3

cer’s account, it did not clearly err in finding that Mills had not
accepted responsibility.
   Mills’ plea agreement did not promise a substantial assistance
departure in return for his cooperation. At the sentencing hearing,
however, he asserted that he was entitled to a departure motion
because he had attempted to provide substantial assistance to law
enforcement authorities after his arrest. He testified that he was frus-
trated in his efforts because the officer working with him was often
unavailable when Mills contacted him. The officer testified that it was
possible that Mills had called while he was hunting on his day off, but
that, during the month that Mills was on bond so that he could cooperate,2
Mills did not provide any useful information about drug dealers, or
arrange a controlled buy, and he refused to provide information about
certain people that the officer wished to pursue. The district court
ruled that there was no basis for a substantial assistance motion.
   When the government has not agreed to request a substantial assis-
tance departure in return for the defendant’s substantial assistance, a
court may review the prosecutor’s decision not to move for a depar-
ture only if the refusal is based on an unconstitutional motive or is not
rationally related to a permissible government objective. See Wade v.
United States, 504 U.S. 181, 185-86 (1992); United States v. Maddox,
48 F.3d 791, 796 (4th Cir. 1995). Before the court may inquire into
the government’s reasons, the defendant must make a "substantial
threshold showing" of impropriety. Wade, 504 U.S. at 186. A descrip-
tion of the defendant’s efforts to provide substantial assistance is not
enough. Id. at 187. Mills failed to make the necessary threshold show-
ing that the government’s decision was not rationally related to a
legitimate end, and he is not entitled to resentencing on this ground.
  We therefore affirm the sentence. 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
  2
   Mills was under home detention, but was permitted to leave his home
during certain hours to associate with drug dealers and attempt to set up
controlled buys.
