United States Court of Appeals
                              FOR THE EIGHTH CIRCUIT
                                    ___________

                                    No. 04-2092
                                    ___________

United States of America,                *
                                         *
      Plaintiff - Appellee,              *
                                         * Appeal from the United States
      v.                                 * District Court for the
                                         * District of Nebraska.
Tracy Vaughn,                            *
                                         *
      Defendant - Appellant.             *
                                    ___________

                               Submitted: December 17, 2004
                                  Filed: June 8, 2005
                                   ___________

Before LOKEN, Chief Judge, MORRIS SHEPPARD ARNOLD and RILEY, Circuit
      Judges.
                              ___________

LOKEN, Chief Judge

      After a bench trial, the district court1 convicted Tracy Vaughn of conspiracy
to distribute fifty grams or more of crack cocaine in violation of 21 U.S.C.
§§ 841(a)(1) and (b)(1). Vaughn appeals, arguing there was insufficient evidence to
support his conviction and challenging the drug quantity finding underlying his 360-
month sentence. We affirm.



      1
       The HONORABLE LAURIE SMITH CAMP, United States District Judge for
the District of Nebraska.
                           I. Sufficiency of the Evidence

       At trial, five admitted conspirators testified for the government that they had
bought crack cocaine from or sold crack cocaine to Vaughn on numerous occasions
during the alleged conspiracy period. The district court’s detailed findings of fact
reviewed this trial testimony, noted that the five witnesses had an incentive to
cooperate with the government but not to testify falsely, further noted that some of
their testimony was corroborated by others, and credited the testimony that they
engaged in on-going crack cocaine transactions with Vaughn.2

       On appeal, Vaughn argues that the district court erred in finding these
witnesses credible because they had been convicted of drug offenses and agreed to
testify against Vaughn in exchange for the possibility of receiving reduced sentences.
In reviewing the sufficiency of the evidence after a bench trial, we apply the same
standard that we apply when reviewing a jury verdict. See United States v. Matra,

, 840 (8th Cir. 1988); United States v. Barletta, 

, 991 (8th
Cir. 1977). It is well-established that “the uncorroborated testimony of an accomplice
is sufficient to sustain a conviction if the testimony is not otherwise incredible or
unsubstantial on its face.” United States v. Dunn, 

, 1281-82 (8th Cir.),
cert. denied, 

(1974). Here, the district court credited the conspirators’
testimony; these credibility findings are “virtually unreviewable on appeal.” United
States v. Candie, 

, 64 (8th Cir. 1992). After careful review of the trial




      2
        In a pro se supplemental brief, Vaughn argues that the district court erred in
crediting the testimony that the drug trafficking involved crack cocaine, because the
conspirators were not qualified experts capable of distinguishing crack from other
forms of cocaine. This argument is without merit. The witnesses were experienced
drug dealers. The district court did not commit clear error in crediting their testimony
that they were selling and buying crack cocaine. See United States v. Marsalla, 

, 1179-80 (8th Cir. 1999).

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record, we conclude that the evidence was more than sufficient to sustain Vaughn’s
conviction.

                                II. Sentencing Issues

       The district court’s post-trial findings of fact included detailed findings as to
the quantities of crack cocaine to which the five conspirator witnesses testified at
trial. Based in large part on those findings, Vaughn’s Presentence Investigation
Report (PSR) recommended that he be held accountable for 2.17 kilograms of crack
cocaine. Vaughn objected to this recommendation, arguing “that there was no direct
evidence of the amount of drugs attributable to [Vaughn] and that amount of drugs
attributed to [him] by the government’s witnesses was vague and incorrect.” At
sentencing, the district court overruled this objection: “Having presided over the trial
of this matter as the finder of fact and law, I agree that the amount of crack cocaine
attributed to [Vaughn] in the PSR is fair and accurate.”

       On appeal, noting that the district court did not recite that its post-trial drug
quantity findings were made beyond a reasonable doubt, Vaughn argues for the first
time that the court violated his Sixth Amendment rights under the Supreme Court’s
post-sentencing decision in Blakely v. Washington, 

(2004). In
considering this contention, we apply the Supreme Court’s more recent clarifying
opinion in United States v. Booker, 

(2005). Because Vaughn failed
to raise the issue at sentencing, we review for plain error. United States v. Pirani, 

(8th Cir. 2005) (en banc).

      We will assume that the district court made its pre-Blakely drug quantity
findings under the preponderance of the evidence standard. But the remedial opinion
in Booker held that such judicial fact-finding for sentencing purposes does not violate




                                          -3-
the Sixth Amendment when made as part of an advisory Guidelines regime.3 Thus,
the “Booker error” in this case was the district court’s understandable error in treating
the Guidelines regime as mandatory. The plain error question, then, is whether
Vaughn has satisfied his burden of demonstrating a “reasonable probability” that the
district court would have imposed a more favorable sentence had the court understood
the Guidelines to be advisory, as now mandated by Booker. We conclude Vaughn
has made no such showing. In imposing the 360-month sentence, the court explained,
“I’ve chosen a sentence at the low end of the guidelines range because I think . . . a
sentence of that substantial length is going to serve all of the goals of the criminal
justice system.” See 

.

       Vaughn argues in the alternative that the evidence at trial did not support the
district court’s drug quantity finding. He relies on the fact that the district court
credited witness Chinn’s testimony that Vaughn supplied Chinn with 13 ounces of
crack cocaine, whereas the government advised the court some months after the trial,
while this appeal was pending, that the government had not called Chinn as a witness
in a subsequent trial because of concerns about his truthfulness in that unrelated
matter. If Chinn’s trial testimony were material to the district court’s drug quantity
finding, we would need to consider whether this new information casts sufficient
doubt on Chinn’s credibility to warrant a remand so that the district court could
consider the question in the first instance. But we conclude that Chinn’s testimony
was not material to the drug quantity issue. The district court attributed 2.17
kilograms of crack to Vaughn for sentencing purposes. This resulted in a base
offense level of 38. See U.S.S.G. § 2D1.1(c)(1). Base offense level 38 applies if the
defendant was responsible for 1.5 kilograms or more of crack cocaine. Chinn’s
testimony attributed 13 additional ounces, or 368.55 grams (one ounce equals 28.35
grams). Subtracting Chinn’s 368.55 grams from the total of 2.17 kilograms still

      3
       For this reason, Vaughn’s pro se argument that the district court violated
Blakely in finding by a preponderance that the conspiracy offense began less than two
years after his release from prison is without merit. See U.S.S.G. § 4A1.1(e).

                                          -4-
leaves Vaughn responsible for well over 1.5 kilograms, so Chinn’s testimony did not
affect Vaughn’s base offense level of 38.

      The judgment of the district court is affirmed.
                     ______________________________




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