United States Court of Appeals
                           FOR THE EIGHTH CIRCUIT
                                    ___________

                                   No. 08-3146
                                   ___________

                                        *
United States of America,               *
                                        *
             Plaintiff – Appellee,      *
                                        * Appeal from the United States
      v.                                * District Court for the
                                        * Eastern District of Missouri.
Barry A. Boyce,                         *
                                        *
                                        *
            Defendant – Appellant.      *
                                   ___________

                             Submitted: April 14, 2009
                                Filed: May 4, 2009
                                 ___________

Before MURPHY, HANSEN, and BYE, Circuit Judges.
                           ___________

MURPHY, Circuit Judge.

      Barry Boyce was convicted of possession with intent to distribute five grams
or more of cocaine base, 21 U.S.C. § 841(a)(1), (b)(1)(B), and sentenced to 262
months on August 25, 2008. Boyce appeals, arguing that the district court1 erred at
sentencing by relying on perjured testimony, giving excessive presumptive weight to
the advisory guidelines, failing to consider all the sentencing factors in 18 U.S.C. §


      1
        The Honorable Jean C. Hamilton, United States District Judge for the Eastern
District of Missouri.
3553(a), and imposing an unreasonable sentence. He also complains that the
government presented perjured testimony and failed timely to disclose evidence
relating to its witnesses. We affirm.

                                           I.

       Boyce was arrested on February 1, 2004 while in possession of approximately
13.5 grams of crack cocaine and nearly $3500. He was charged with four counts of
possession and distribution of cocaine base, and he pled guilty to one count of
possession with intent to distribute five grams or more of cocaine base. He was
originally sentenced in 2004, subsequent to the Supreme Court's decision in Blakely
v. Washington, 

(2004). The district court interpreted that decision to
prohibit it from finding facts beyond those admitted by Boyce in his plea agreement
and sentenced him to 63 months. The government appealed, and we vacated and
remanded after United States v. Booker, 

(2005), made it clear that a
sentencing court could find facts in an advisory guideline system. United States v.
Boyce, No. 04-3429, 

(8th Cir. July 5, 2005) (per curiam). At his
second sentencing in 2006 the district court found that Boyce was responsible for
distributing more than 1.5 kilograms of cocaine base and imposed two level
enhancements under U.S.S.G. § 2D1.1(b)(1) and § 3B1.1(c). Boyce was then
sentenced to 324 months, and he appealed. We reversed after questioning the
sufficiency of the evidence related to his criminal history. United States v. Boyce, 

, 1102 (8th Cir. 2007).

      At his most recent sentencing hearing, the government presented evidence that
Boyce had a prior conviction for assault and had committed the instant offense within
two years of his release from state custody for that felony. The district court overruled
Boyce's objections to the introduction of new evidence relevant to his criminal history
and to the total offense level determined in 2006. His advisory guideline range was
computed to be 262–327 months, and the district court sentenced him to 262 months.

                                          -2-
       Boyce appeals, arguing that the district court relied on unreliable testimony in
determining his offense level and erred by considering evidence about his criminal
history offered for the first time at his 2008 sentencing hearing. He contends the court
gave inadequate consideration to the § 3553(a) factors and treated the sentencing
guidelines as mandatory. Finally, he argues that the government violated its
obligation to disclose exculpatory evidence and knowingly presented perjured
testimony about his drug dealing at his 2006 sentencing hearing.

                                          II.

       Boyce argues that there was insufficient evidence establishing his relevant
conduct because the government witnesses were unreliable. The district court found
that Boyce was responsible for over 1.5 kilograms of cocaine base, considerably more
than the 13.55 grams he possessed at the time of his arrest. A district court makes
findings about relevant conduct by a preponderance of the evidence, see United States
v. Villareal-Amarillas, No. 07-3616, 

(8th Cir. Apr. 9, 2009), and
we review for clear error. United States v. Vickers, 

, 1120 (8th Cir.
2008). The district court based its drug quantity findings on testimony given at the
2006 sentencing hearing. James Baker testified that he had purchased three ounces
of cocaine from Boyce and that Boyce had confided to him that he had sold at least
five kilograms of cocaine base each week in 2003. Rodney Townsend testified that
on four occasions he had delivered approximately 15 ounces of cocaine to Boyce and
that Boyce would convert all of the powder cocaine to crack cocaine and sell it.

      Boyce argues that this testimony was unreliable because each witness had been
promised a reduction in his own sentence in exchange for testifying. This does not
make their testimony inherently unreliable, however. Cf. United States v. Maggard,

, 847 (8th Cir. 1998). Boyce contends that Baker was unreliable because
he wrongly testified that he had no prior criminal convictions and that Boyce claimed
to have sold a quantity of crack cocaine that would have made him extremely wealthy,

                                          -3-
which he was not at the time of his arrest. Boyce argues that Rodney Townsend was
regularly using marijuana when he testified and that Townsend claimed to have
received drugs from Boyce during the time that Boyce was incarcerated.

      The district court found, however, that there was "some credibility in the
testimony of Baker and Townsend" with regard to drug quantity. The finder of fact
may accept the parts of a witness's testimony that it finds credible while rejecting any
portion it finds implausible or unreliable. See United States v. Hall, 

,
1300 (8th Cir. 1993). Findings about the credibility of witnesses are "virtually
unreviewable on appeal." United States v. Gomez-Perez, 

, 743 (8th Cir.
2006) (quoting United States v. Santana, 

, 864 (1998)). We cannot
conclude from this record that the district court erred in basing its finding about the
quantity and type of drugs that Boyce sold on the testimony of these witnesses.

        The district court also found that Boyce had possessed a dangerous weapon in
connection with his offense. A § 2D1.1(b)(1) enhancement is appropriate if the
government shows "that a weapon was present and that it is not clearly improbable
that the weapon was connected with the criminal activity." United States v. Belitz,

, 817 (8th Cir. 1998); see also United States v. Burling, 

,
750 (8th Cir. 2005) (constructive possession is sufficient). Boyce contends that there
was no definitive testimony placing a firearm near him during a cocaine sale. Police
seized a .45 caliber Glock handgun and over 100 rounds of ammunition from the
house where Boyce was arrested on February 1, 2004. Randall Lewis testified that he
saw Boyce with a Glock handgun around Christmas 2003, and Baker testified that he
saw Boyce with a firearm during two separate drug sales. Baker also claimed that
Boyce had told him about shooting Penny Coleman, another drug dealer. Townsend
testified that he was present during the Coleman shooting and that Boyce had used an
SKS rifle. The district court found that there was sufficient evidence that firearms
were present and involved in Boyce's drug transactions to support a § 2D1.1(b)(1)
enhancement. We conclude that the district court did not err in making this finding.

                                          -4-
       The district court applied a two level enhancement under § 3B1.1(c) for Boyce's
role as a leader of criminal activity. Townsend testified that he belonged to a group
that distributed cocaine for and protected Boyce. Although Baker was not a member,
he corroborated Townsend's identifications of other members. The district court
found that Baker and Townsend were knowledgeable and reliable witnesses regarding
the drug trade in southeastern Missouri and that their testimony that Boyce was "at the
center of a rather vibrant . . . crack cocaine ring" was "certainly credible." The record
amply supports the district court's finding that Boyce was a leader of criminal activity,
and the two level enhancement was not erroneous.

       Boyce also argues that there was insufficient evidence to place him in criminal
history category III because new evidence of his criminal history should not have been
admitted at the 2008 hearing. However, our remand order specifically permitted the
district court to consider new evidence related to Boyce's criminal history. 

.

                                          III.

      Boyce claims that the district court committed procedural error by giving
excessive presumptive weight to the guidelines and failing to consider all the §
3553(a) factors. He contends that the district court gave insufficient weight to his
personal characteristics, failed to consider the Sentencing Commission's policy
guidance regarding the crack and powder cocaine sentencing disparity, and did not
consider disparities among similarly situated defendants. 18 U.S.C. § 3553(a)(1), (5),
(6). Boyce objected on these grounds at the sentencing hearing so our review is for
abuse of discretion. See Gall v. United States, 

, 597 (2007).

      At sentencing the district court read a letter from Boyce's aunt explaining his
disadvantaged childhood and heard Boyce discuss his children and his post arrest
rehabilitation. The district court also noted the seriousness of Boyce's conduct and

                                          -5-
imposed a sentence at the low end of the guideline range, stating that such a sentence
would address the sentencing objectives of just punishment, general deterrence, and
incapacitation. See 18 U.S.C. § 3553(a)(2). The district court twice stated that it had
considered the provisions of § 3553(a), and such references generally are sufficient
to show "that the district court was aware of the entire contents of the relevant statute."
United States v. Perkins, 

, 1111 (8th Cir. 2008) (quoting United States
v. White Face, 

, 740 (8th Cir. 2004)). Here, the district judge was very
familiar with Boyce's history and characteristics. See United States v. Franklin, 

, 607 (8th Cir. 2005). Based on the entire sentencing record, we conclude
that the district court adequately considered the § 3553(a) factors and did not give the
advisory guidelines excessive weight.

       Boyce argues that the district court did not consider the "need to avoid
unwarranted sentence disparities among defendants with similar records who have
been found guilty of similar conduct," 18 U.S.C. § 3553(a)(6), but he does not
establish that other defendants were similarly situated in terms of conduct, criminal
history, and acceptance of responsibility. Boyce also contends that the district court
gave inadequate weight to the Sentencing Commission's policy statements regarding
the 100:1 quantity ratio for crack and powder cocaine. Both Boyce and the
government commented on the district court's discretion to consider this disparity, and
we may presume the district court was aware of this policy guidance. The district
court need not respond to every argument advanced by a defendant, and the extent of
explanation required varies according to the circumstances of the case. See United
States v. Lee, 

, 600 (8th Cir. 2009). Less extensive explanation is
necessary when a guideline sentence is imposed. Rita v. United States, 

,

, 2469 (2007). We are satisfied that the district court considered
Boyce's arguments and adequately stated the reasons for its judgment. See United
States v. Sigala, 

, 851 (8th Cir. 2008).




                                           -6-
      Finally, Boyce contends that his sentence is substantively unreasonable. We
review the reasonableness of a sentence for abuse of discretion and treat a sentence
within the guideline range as presumptively reasonable. United States v. Torres, 

, 747–48 (8th Cir. 2009). Boyce's arguments for why he should receive a
below guideline sentence are not compelling enough to overcome this presumption.

                                          IV.

       Boyce contends that the government failed to identify its witnesses prior to the
2006 sentencing hearing and did not disclose their conviction records and prior
statements in violation of Brady v. Maryland, 

(1972). He also argues
that the government knowingly presented false testimony and thereby deprived him
of due process. See Napue v. Illinois, 

, 269 (1959). Boyce originally
raised these issues in an unsuccessful motion to vacate his 2006 sentence and then
again in his second appeal, after which we vacated his sentence on other grounds.

       The government presented no new evidence about Boyce's relevant conduct at
the 2008 hearing, but by then Boyce had obtained the conviction records and prior
statements of Baker, Townsend, and Lewis. Although he argued that all three were
unreliable, he did not renew his claim that the government knew about their alleged
perjury or argue that he had been prejudiced by the earlier withholding of evidence.
We therefore review for plain error his current argument that his sentencing was not
consistent with due process. Fed. R. Crim. P. 52(b).

       Boyce cites no authority requiring the government to provide a defendant with
its witness list prior to a sentencing hearing, only that the government's failure to do
so violated his due process and confrontation rights. The mere identity of witnesses
is not exculpatory and is not covered by Brady. See United States v. Aleman, 

, 1164 (8th Cir. 2008). Even if the confrontation clause applied at
sentencing, see United States v. Wallace, 

, 1048 (8th Cir. 2005) (per
curiam), Boyce was able to cross examine each of the government's witnesses.

                                          -7-
       Boyce also argues that the government violated Brady and its discovery
obligations by not disclosing the criminal records of Baker, Townsend, and Lewis
prior to the 2006 hearing. Boyce argues that these records would have been valuable
for impeaching the witnesses, see Giglio v. United States, 

, 154 (1972),
particularly Baker, who stated on cross examination that he had no prior convictions.
The government did not present the witnesses as law abiding citizens, but rather as
participants in the local cocaine trade which significantly reduced the impeachment
value of their conviction records. See United States v. Quintanilla, 

, 699
(8th Cir. 1994). Boyce obtained the conviction records in time for the 2008 hearing
and used those records to argue that the witnesses lacked credibility. Because the
district court knew about the prior convictions when it imposed his 2008 sentence,
Boyce was not prejudiced by the unavailability of this evidence during the 2006
hearing.

       Boyce contends that the government failed to produce prior statements by
Baker, Townsend, and Lewis that were subject to Criminal Rule 26.2 before the
sentencing hearing. See Fed. R. Crim. P. 32(i)(2). The government produced the
statements after their direct testimony as Rule 26.2 requires. Boyce argues that the
government had promised to produce these statements at an earlier point, but that
commitment pertained to a trial that did not occur because Boyce pled guilty.
Although Boyce asserts that Brady required the statements to be disclosed earlier, he
never explains how they were exculpatory. Boyce had the opportunity at the 2008
hearing to bring to the district court's attention any exculpatory content of these
statements, so he cannot show a reasonable probability that any delay in disclosure
affected his sentencing.

       Boyce also argues that the government presented testimony it knew to be false.
See 

. To prove a violation of due process, Boyce must
establish that the prosecution used perjured testimony, knew or should have known
of the perjury, and that there is a "reasonable likelihood that the perjured testimony

                                         -8-
could have affected the [court's] judgment." United States v. Martin, 

, 770
(8th Cir. 1995) (internal quotations omitted).

       According to Boyce, Baker committed perjury by testifying that he had no prior
convictions, that he had known Boyce before 2005, and that Boyce had claimed to
have sold large quantities of drugs. Boyce only has direct proof that the first
statement is false, but Baker did not mislead the court about his criminal record
because he had readily admitted that he was awaiting sentencing. See United States
v. Thomas, 

, 489 (8th Cir. 1996) (perjury requires wilful intent to provide
false testimony, rather than confusion or mistake). The district court was not misled
about Baker's credibility in 2006, and any misunderstanding was resolved by the 2008
sentencing proceedings.

        Boyce asserts that Lewis committed perjury when he stated that he purchased
cocaine from Boyce nearly every day during 2003, which was inconsistent with his
later testimony that he could only remember transactions during December 2003. This
inconsistency was immediately apparent to the district court, which determined that
Lewis's testimony was too confused to be relied upon for the drug quantity finding.
This was therefore not the kind of undisclosed false statement that creates a due
process concern. See United States v. Nelson, 

, 443 (8th Cir. 1992)
("[M]ere inconsistency is not necessarily equated with perjury and every contradiction
may not be material"). Boyce also notes that Lewis and Townsend claimed they had
obtained drugs from him during a time when he was incarcerated; the government
concedes that these statements were false. We cannot conclude that there is a
reasonable likelihood that the false statements affected Boyce's sentence, however,
because the court was informed of this discrepancy during the 2008 hearing. At the
time of sentencing the district court was aware of the actual and alleged false
statements by the witnesses. As a result, we need not speculate whether the court's
knowledge of the false statements might have affected the judgment—we know that
the sentence reflects the corrected facts. In sum, we conclude that Boyce's sentencing
was not procedurally defective based on any alleged misconduct by the government.

                                         -9-
                                         V.

       We conclude that the government did not violate any discovery obligations
in respect to Boyce's sentencing or its duties under Brady, nor did it knowingly
present false testimony. The district court did not clearly err in relying on
testimony that it found credible in determining Boyce's relevant conduct, and it did
not treat the sentencing guidelines as mandatory. Before imposing the sentence it
considered the § 3553(a) factors and explained its reasons. In sum, the district
court committed no procedural error and imposed a reasonable sentence. For these
reasons we affirm the judgment.

                       _____________________________




                                        -10-