NONPRECEDENTIAL DISPOSITION
                     To be cited only in accordance with
                             Fed. R. App. P. 32.1



           United States Court of Appeals
                            For the Seventh Circuit
                            Chicago, Illinois 60604

                           Submitted February 13, 2008
                            Decided February 14, 2008

                                     Before

                   Hon. JOEL M. FLAUM, Circuit Judge

                   Hon. TERENCE T. EVANS, Circuit Judge

                   Hon. ANN CLAIRE WILLIAMS, Circuit Judge

No. 07-3346

UNITED STATES OF AMERICA,                     Appeal from the United States District
    Plaintiff-Appellee,                       Court for the Southern District of
                                              Indiana, Terra Haute Division
      v.
                                              No. 06CR00020
RONALD FOSTER,
    Defendant-Appellant.                      Larry J. McKinney,
                                              Judge.

                                   ORDER

      Ronald Foster pleaded guilty to possession of a prohibited object in prison
and received a 30-month sentence to run consecutively with the term he was
already serving. He filed a notice of appeal, but appointed counsel moves to
withdraw under Anders v. California, 

(1967), because counsel cannot
discern any nonfrivolous ground for appeal. Foster accepted our invitation to
respond to his lawyer’s submission. See CIR. R. 51(b). Limiting our review to the
potential issues identified in counsel’s facially adequate brief and in Foster’s
submission, see United States v. Schuh, 

, 973-74 (7th Cir. 2002), we
grant counsel’s motion and dismiss the appeal.

      While Foster was incarcerated at the Federal Correctional Institution in
Terra Haute, Indiana, a prison guard saw him pull something from his waistband
and throw it to the ground. The guard retrieved the object, which he discovered
No. 07-3346                                                                     Page 2
was a sharpened piece of wood one inch wide and six-and-three-quarter inches long.
Before any criminal prosecution, the Bureau of Prisons charged Foster with a
disciplinary violation to which he admitted when he appeared before the Unit
Disciplinary Committee and later before a Disciplinary Hearing Officer. In an
interview with Special Investigative Agent Eric Jaeger, he again admitted to having
possessed the object.

       When the government later brought criminal charges against Foster for
possession of a prohibited object in prison, see 18 U.S.C. § 1791(a)(2), Foster sought
to suppress his multiple admissions of guilt as involuntary. He testified at the
suppression hearing that one of the two BOP employees who comprised the
Committee promised him that if he admitted the disciplinary violation he would not
be criminally prosecuted. He also testified that the Disciplinary Hearing Officer
and Agent Jaeger both repeated the promise. Foster claimed that he admitted to
having the object only because he believed that doing so would relieve him from
prosecution. And he also claimed that Jaeger gave him incomplete Miranda
warnings telling him, “you have a right to an attorney present, but you don’t need
no attorney present, do you?”

       At the suppression hearing, the members of the Disciplinary Committee, the
Hearing Officer, and Jeager also testified. One Committee member specifically
asserted that she did not tell Foster that he would avoid prosecution if he confessed
and did not hear anyone else make a similar promise. The other member of the
Committee as well as the Disciplinary Hearing Officer did not have specific
memories of Foster, but both testified that they had never made such a promise to
an inmate. Jaeger testified that he properly advised Foster of his Miranda rights,
that he made no promises to Foster regarding prosecution, and that Foster signed a
Miranda-waiver form before admitting to possessing the object. The district court
found all four government employees to be credible and Foster’s testimony to be
incredible. Thus, the district court held, his statements were voluntary and would
not be suppressed. Foster then pleaded guilty.

       In his Anders submission, counsel identifies the denial of Foster’s motion to
suppress as the sole potential ground for appeal. This is appropriate as Foster’s
plea agreement contains a facially valid waiver of his right to appeal on “any
ground” except the denial of his motion to suppress. We will enforce an appeal
waiver that was entered into as part of a voluntary guilty plea, Nunez v. United
States, 

, 545-46 (7th Cir. 2007), and neither counsel nor Foster himself
suggest that his guilty plea was anything but voluntary.

       Regarding the denial of Foster’s motion to suppress, counsel first notes,
correctly, that it would be frivolous to ask that we reverse the district court’s
credibility findings. We would reverse a credibility finding only if it were
No. 07-3346                                                                     Page 3
unbelievable as a matter of law; that is, if it were “impossible under the laws of
nature.” United States v. Ortiz, 

, 1039 (7th Cir. 2005). Under this
standard, Foster could not reasonably argue that his statements were not voluntary
or did not follow proper Miranda warnings. Thus, it would be frivolous to argue
that failing to suppress the statements was error.

       In his own submission, Foster first argues that the district court’s ruling on
his suppression motion was not supported by sufficient evidence and he argues
against the Anders procedure generally. His sufficiency-of-evidence challenge is
frivolous. If testimony of a single eyewitness is sufficient to support a
determination of fact underlying guilt, Hayes v. Battaglia, 

, 938 (7th
Cir. 2005), then the testimony of four eyewitnesses is sufficient to support a factual
determination underlying the denial of a suppression motion. Thus, Foster cannot
demonstrate anything approaching the clear error required for us to disturb factual
findings underlying a denial of a suppression motion. United States v. Riley, 

, 808 (7th Cir. 2007). And the Supreme Court has already rejected Foster’s
objections to the Anders procedure. See, e.g., Smith v. Robbins, 

(2000).

       Finally, Foster points out that he “agreed to plead guilty only if his right to
bring the suppression claim before the appeals court [was retained].” He seems to
believe that his counsel’s Anders filing has denied him the benefit of his plea
bargain. Not so. Both we and Foster’s counsel have actually considered the
possibility of an appeal of the suppression claim, and we agree with counsel that it
would be frivolous. But no defendant has the right to bring a frivolous appeal,
United States v. Bullion, 

, 575 (7th Cir. 2006), and the reservation of
an issue for appeal in a plea bargain cannot possibly trump a lawyer’s ethical duty
not to present frivolous arguments, see McCoy v. Court of Appeals, 

,
436 (1998); United States v. Gomez, 

, 926 (7th Cir. 1994).

       Foster’s only potentially nonfrivolous claim—and we do not suggest that the
facts would support it because we do not know them—would be that his guilty plea
was involuntary because it was based on a false assurance by counsel that a viable
appeal was in the offing. But any such claim—if Foster did indeed wish to make
it—is best pursued as ineffective assistance of counsel and Foster states in his sub-
mission that he is not claiming ineffective assistance at this stage. Besides, doing
so would be more appropriate in a collateral proceeding under 28 U.S.C. § 2255
where a fuller record may be developed. See Massaro v. United States, 

, 504-05 (2003); United States v. Harris, 

, 557-58 (7th Cir. 2005).

      For the foregoing reasons, counsel’s motion to withdraw is GRANTED and
the appeal is DISMISSED.