                       AMENDED OPINION
                          PUBLISHED

UNITED STATES COURT OF APPEALS
                FOR THE FOURTH CIRCUIT


DEXTER LEE VINSON,                    
              Petitioner-Appellant,
                 v.
                                                  No. 04-29
WILLIAM PAGE TRUE, Warden,
Sussex I State Prison,
               Respondent-Appellee.
                                      
           Appeal from the United States District Court
         for the Eastern District of Virginia, at Richmond.
                 James R. Spencer, District Judge.
                          (CA-02-106-3)

                       Argued: October 26, 2005

                      Decided: December 15, 2005

            Amended Opinion Filed: February 1, 2006

    Before WIDENER, MOTZ, and DUNCAN, Circuit Judges.



Affirmed by published opinion. Judge Motz wrote the opinion, in
which Judge Widener and Judge Duncan joined.


                             COUNSEL

ARGUED: Matthew Leland Engle, VIRGINIA CAPITAL REPRE-
SENTATION RESOURCE CENTER, Charlottesville, Virginia, for
Appellant. Katherine P. Baldwin, Senior Assistant Attorney General,
2                          VINSON v. TRUE
OFFICE OF THE ATTORNEY GENERAL OF VIRGINIA, Rich-
mond, Virginia, for Appellee. ON BRIEF: Robert E. Lee, Jr., VIR-
GINIA CAPITAL REPRESENTATION RESOURCE CENTER,
Charlottesville, Virginia; Mark E. Olive, Tallahassee, Florida, for
Appellant. Judith W. Jagdmann, Attorney General of Virginia, Rich-
mond, Virginia, for Appellee.


                             OPINION

DIANA GRIBBON MOTZ, Circuit Judge:

   Dexter Lee Vinson appeals the denial of his federal habeas petition,
in which he sought relief from a death sentence. We granted a certifi-
cate of appealability on three issues: (1) whether the district court
erred in failing to hold an evidentiary hearing on Vinson’s claim that
his trial counsel operated under an unconstitutional conflict of inter-
est; (2) whether Vinson was denied effective assistance of counsel;
and (3) whether the state failed to disclose material exculpatory evi-
dence. For the reasons that follow, we affirm the district court’s
denial of habeas relief.

                                  I.

   In December 1998, a Virginia jury convicted Dexter Lee Vinson of
the capital murder of Angela Felton, object sexual penetration, abduc-
tion with intent to defile, and carjacking.1 In a separate sentencing
proceeding, the jury sentenced Vinson to life in prison for each of the
three non-capital offenses, and to death on the capital murder charge,
finding that the crime was "outrageously or wantonly vile, horrible or
inhuman in that it involved torture, depravity of mind, aggravated bat-
tery to the victim," and that there was "a probability that he would
commit criminal acts of violence that would constitute a continuing
serious threat to society." The Supreme Court of Virginia affirmed.
    1
   A description of the underlying facts involved in these dreadful
crimes can be found in the Supreme Court of Virginia’s decision on Vin-
son’s direct appeal. See Vinson v. Commonwealth, 522 S.E.2d 170, 173-
75 (Va. 1999).
                             VINSON v. TRUE                             3
Vinson v. Commonwealth, 522 S.E.2d 170 (Va. 1999). The Supreme
Court of the United States denied certiorari. Vinson v. Common-
wealth, 530 U.S. 1218 (2000). Vinson then filed a petition for a writ
of habeas corpus with the Supreme Court of Virginia, which it dis-
missed in November 2001. An execution date was subsequently set
for February 28, 2002, but the United States District Court for the
Eastern District of Virginia stayed the execution on February 25,
2002. Vinson then filed a petition for federal habeas relief with the
district court, which ultimately denied him any relief and dismissed
his petition. We granted Vinson a certificate of appealability limited
to the three issues enumerated above.

   Under the Anti-Terrorism and Effective Death Penalty Act of 1996
("AEDPA"), 28 U.S.C.A. § 2254(d) (West Supp. 2005), federal courts
reviewing petitions for habeas relief must give great deference to state
court judgments on the merits. A writ should not be granted on any
claim adjudicated on the merits by the state court unless the decision
was "contrary to, or involved an unreasonable application of, clearly
established Federal law, as determined by the Supreme Court of the
United States," or was "based on an unreasonable determination of the
facts in light of the evidence presented in the State court proceeding."
Id.

                                   II.

   Vinson initially contends that the district court erred in not granting
him an evidentiary hearing on the question of whether his trial coun-
sel labored under a conflict of interest.

   Vinson argues that under Townsend v. Sain, 372 U.S. 293 (1963)
and Keeney v. Tamayo-Reyes, 504 U.S. 1 (1992), a federal habeas
court must grant an evidentiary hearing to determine whether an
actual conflict of interest exists. Townsend and Keeney establish that
a habeas petitioner "is entitled to an evidentiary hearing if he can
show cause for his failure to develop the facts in state-court proceed-
ings and actual prejudice resulting from that failure," or that "a funda-
mental miscarriage of justice would result from failure to hold a
federal evidentiary hearing." Keeney, 504 U.S. at 11-12.

  Vinson relies on Cuyler v. Sullivan, 446 U.S. 335 (1980) for his
conflict of interest claim. In Sullivan, the Supreme Court held that
4                           VINSON v. TRUE
"[i]n order to establish a violation of the Sixth Amendment, a defen-
dant who raised no objection at trial must demonstrate that an actual
conflict of interest adversely affected his lawyer’s performance." Id.
at 348. If a defendant successfully demonstrates that "a conflict of
interest actually affected the adequacy of his representation," he "need
not demonstrate prejudice in order to obtain relief." Id. at 349-50.

   Vinson’s conflict of interest claim arises from the undisputed fact
that during his trial, Vinson’s "second chair" counsel, Tanya Lomax,
was suing Vinson’s lead counsel, John Underwood, for employment
discrimination that had allegedly occurred during Lomax’s employ-
ment at the Portsmouth Public Defender’s Office. Vinson contends
that the separate employment litigation between Lomax and Under-
wood adversely affected his representation in two ways: first, Lomax
suffered health problems resulting from the stress of the litigation;
and second, the way Underwood and Lomax divided the work and
responsibilities of his case into distinct guilt and sentencing phases
left Lomax inadequately supervised by Underwood.

   When Vinson raised this claim for the first time in the state habeas
proceedings, the Supreme Court of Virginia held that the claim was
barred under state law because it could have been brought on direct
appeal. See Slayton v. Parrigan, 205 S.E.2d 680 (1974). This proce-
dural bar constitutes an adequate and independent state law ground
for default. See Wright v. Angelone, 151 F.3d 151, 159-60 (4th Cir.
1998). Absent a fundamental miscarriage of justice, which Vinson
does not assert, federal habeas courts may not review procedurally
barred claims "unless the prisoner can demonstrate cause for the
default and actual prejudice as a result of the alleged violation of fed-
eral law." Coleman v. Thompson, 501 U.S. 722, 750 (1991). To estab-
lish "cause," a prisoner must "show that some objective factor
external to the defense impeded counsel’s efforts to comply with the
State’s procedural rule." Murray v. Carrier, 477 U.S. 478, 488 (1986)
(emphasis added). This requires a demonstration that "the factual or
legal basis for the claim was not reasonably available to the claimant
at the time of the state proceeding." Roach v. Angelone, 176 F.3d 210,
222 (4th Cir. 1999) (citing McCleskey v. Zant, 499 U.S. 467, 494
(1991)). A petitioner may not establish cause "by pointing to evidence
that the petitioner ‘knew about or could have discovered’ through a
‘reasonable investigation.’" Basden v. Lee, 290 F.3d 602, 618 (4th
                              VINSON v. TRUE                                5
Cir. 2002) (quoting McCleskey, 499 U.S. at 497-98); see also Rose v.
Lee, 252 F.3d 676, 687 (4th Cir. 2001).

   Rather than relying on evidence not "reasonably available" to him
"at the time of the state proceeding," Vinson instead "point[s] to evi-
dence" that he clearly "knew about" at the time of his trial. Prior to
trial Lomax informed Vinson of the facts giving rise to the asserted
conflict, and Vinson consented to representation by "conflicted" coun-
sel. In a sworn, written waiver, Vinson explicitly stated that "[w]ith
full knowledge and understanding of Attorney Lomax’s complaint
and disclosure, I freely and voluntarily give my consent to have Attor-
ney Lomax continue to represent me in the above-styled matter." In
Vinson’s presence, defense counsel then presented Vinson’s waiver
to the trial court. In light of this waiver, it is plain that the facts of the
alleged conflict between Lomax and Underwood were not only avail-
able to Vinson, but were specifically presented to him for his consid-
eration and consent. His voluntary, knowing, and informed decision
to continue with Lomax as his counsel precludes any argument that
a factor external to the defense caused the procedural default. Vinson
thus does not depend on facts that could not have been previously dis-
covered, and he cannot establish cause to overcome the procedural bar.2

   In addition to its holding that the claim was procedurally barred
from habeas review, the Supreme Court of Virginia also rejected Vin-
son’s conflict claim on the merits. Sworn statements from both
Underwood and Lomax stated inter alia that the discrimination suit
had no effect on their representation of Vinson, that the two lawyers
had a good working relationship with no friction, problems or issues
during their representation of Vinson. The court explained that Vin-
son was fully informed by counsel of the details of the conflict and
was told he could obtain alternate counsel, but that he decided to con-
tinue with Lomax as his counsel. Consequently, the state court held
that there was "no evidence that an actual conflict of interest existed
between lawyer and client."

  Given these facts, we can hardly find the state court’s rejection of
Vinson’s conflict of interest claim on the merits contrary to or an
  2
   Because Vinson cannot show cause, his Keeney claim also fails. 504
U.S. at 11-12.
6                            VINSON v. TRUE
unreasonable application of clearly established Supreme Court prece-
dent. See id. § 2254(d). The Court has explained that to succeed on
a conflict of interest claim, a petitioner must establish that "‘his coun-
sel actively represented conflicting interests,’" and that this conflict
"adversely affected his counsel’s performance." Mickens v. Taylor,
535 U.S. 162, 174-75 (2002) (quoting Sullivan, 446 U.S. at 350)
(emphasis added by Mickens Court). Here the asserted conflict does
not involve Vinson’s counsel’s "active representation" of "conflicting
interests" — Vinson makes no claim that Underwood and Lomax rep-
resented individuals with conflicting interests. Rather, this is a case
in which Vinson’s two attorneys had an independent and unrelated
conflict between themselves.

   In sum, we must reject Vinson’s argument that the district court
erred in refusing to provide him an evidentiary hearing on his conflict
claim. The facts underlying Vinson’s claim were available to him at
the time of the state court proceedings, he expressly consented to any
alleged conflict, and he does not proffer facts that establish constitu-
tional error.

                                   III.

   Vinson next asserts that he was denied effective assistance of coun-
sel in violation of Strickland v. Washington, 466 U.S. 668 (1984).

   To prove a Sixth Amendment violation under Strickland a defen-
dant must demonstrate "that counsel’s performance was deficient,"
and that this "deficient performance prejudiced the defense." Id. at
687. To succeed in showing prejudice, a defendant must demonstrate
that there is a "reasonable probability" that absent the alleged errors,
"the result of the proceeding would have been different." Id. at 694.

   Vinson raises several ineffective assistance contentions. He chal-
lenges various trial decisions of his lawyers, their preparation of miti-
gation and other sentencing evidence, and their response to
prosecution evidence as to future dangerousness. The Supreme Court
of Virginia adjudicated each of these claims on the merits and deter-
mined that Vinson had failed to establish ineffective assistance under
Strickland. For the reasons that follow, we conclude that none of the
Virginia court’s rulings constitutes an unreasonable factual determi-
                             VINSON v. TRUE                             7
nation or is contrary to or an unreasonable application of Supreme
Court precedent.

   Vinson argues that his counsel failed to sufficiently investigate the
nature and extent of the perjured testimony of a grand jury witness,
Priscilla Turner, prior to deciding not to call her as a witness at trial,
and that they failed to object to assertedly erroneous statements made
by the prosecutor in closing arguments. The state court examined
these allegations, determined that Vinson’s counsel made these deci-
sions for strategic reasons, and found that neither decision violated
the performance or prejudice prong of Strickland. On habeas review,
a federal court generally credits "plausible strategic judgments in the
trial of a state case." Bunch v. Thompson, 949 F.2d 1354, 1364 (4th
Cir. 1991). Of course, we would not regard as tactical a decision by
counsel if it made no sense or was unreasonable "under prevailing
professional norms." See Wiggins v. Smith, 539 U.S. 510, 521-24
(2003). But that is not the case here.

   The Virginia court also carefully considered Vinson’s claims that
his counsel did not adequately present the argument that Vinson
lacked the requisite intent to defile, did not provide Vinson’s court-
appointed psychologist, Dr. Schlichter, with adequate information,
and failed to investigate and present evidence of Vinson’s background
for mitigation purposes. The state court rejected these contentions,
finding that presenting evidence as to whether Vinson had the requi-
site intent to defile would have been inconsistent with Vinson’s
defense that he did not commit the crime at all. The court further
found that counsel responded to Dr. Schlichter’s requests for informa-
tion, secured an additional expert witness at the doctor’s request, and
spoke with him on numerous occasions.

   The record also reveals that, although they were requested to sup-
ply mitigation information, Vinson and his family failed to do so, but
that nevertheless defense counsel independently discovered mitigation
evidence. At sentencing, Vinson’s counsel presented a mitigation case
that included Vinson’s school records and favorable testimony from
Vinson’s mother, his step-father, two court-appointed expert wit-
nesses, a previous employer, Vinson’s high school band leader, a
parole officer, and a church leader. The case at hand thus stands in
stark contrast to Wiggins, on which Vinson heavily relies. There, the
8                           VINSON v. TRUE
Court found constitutionally ineffective counsel who relied solely on
three documents and failed to investigate further or present any miti-
gation evidence on the defendant’s background despite information in
these documents that could have been used to uncover helpful mitiga-
tion information. Wiggins, 539 U.S. at 523-26.

   Finally, the Supreme Court of Virginia examined Vinson’s argu-
ment that counsel failed to respond sufficiently to the prosecution’s
expert testimony as to future dangerousness. Vinson’s counsel
explained that she relied on the defense expert’s advice about how
best to discredit the prosecution’s expert. She thus focused her cross-
examination on the fact that the prosecution’s expert made his conclu-
sions after meeting with Vinson for only an hour, and without con-
ducting any tests of his own. The court concluded that this reliance
on the defense expert’s advice did not violate the performance prong
of Strickland. We do not find this assessment of Lomax’s method and
strategy of examination to be unreasonable or contrary to Strickland.

   All of Vinson’s ineffective assistance of counsel claims were
deemed insufficient to satisfy either the performance or prejudice
prongs of Strickland by the Virginia court, and we conclude that these
holdings are neither contrary to nor involve an unreasonable applica-
tion of established Supreme Court precedent. These claims therefore
provide no basis for habeas relief.

                                  IV.

   Vinson also asserts entitlement to habeas relief on the ground that
Virginia withheld material exculpatory evidence from him in viola-
tion of Brady v. Maryland, 373 U.S. 83 (1965).

   Under Brady, "the suppression by the prosecution of evidence
favorable to an accused upon request violates due process where the
evidence is material either to guilt or to punishment, irrespective of
the good faith or bad faith of the prosecution." Id. at 87. To succeed
on a Brady claim, the accused must prove that the evidence sup-
pressed is favorable to him, either because it is exculpatory or because
it has some impeaching value; that the prosecution suppressed the evi-
dence; and that prejudice resulted from the suppression. Strickler v.
Greene, 527 U.S. 263, 281-82 (1999). Prejudice exists when there is
                            VINSON v. TRUE                             9
a reasonable probability that, had the prosecution disclosed the sup-
pressed evidence, the result of the trial would have been different. Id.
at 289. Vinson presents several Brady claims, each of which the
Supreme Court of Virginia rejected on the merits.

   Vinson contends that the prosecution inadequately disclosed the
extent to which one of its grand jury witnesses, Priscilla Turner, per-
jured herself. Rather than informing Vinson that Turner’s entire testi-
mony was false, the Government’s disclosure indicated that one part
of her testimony was false and that it would not call her as a witness
at trial.3 The Supreme Court of Virginia, noting that "the Common-
wealth attached Turner’s statement to the police" to its Supplemental
Discovery and Exculpatory Evidence submission and "informed the
defense that Turner would not be testifying at trial," determined that
that disclosure was constitutionally sufficient. We cannot hold the
state court’s determination contrary to, or an unreasonable application
of, Brady. In fact, in sworn affidavits, defense counsel stated that
based on the Government’s disclosure, they proceeded as if Turner’s
entire testimony were false. Thus, the state court’s conclusion that the
disclosure sufficed to satisfy Brady was hardly unreasonable.

   Other asserted Brady violations center on the testimony of Vertley
Hunter, a critical eyewitness who testified for the Government. Vin-
son contends that Hunter made several exculpatory and material state-
ments that were not disclosed to him at the time of his trial. He argues
that Hunter made a statement contained in some handwritten notes in
the prosecution’s files in which she claimed to have seen the perpetra-
  3
    Related to this argument is Vinson’s contention that the Govern-
ment’s insufficient disclosure that perjured testimony was used to obtain
his indictment violated his rights under Brady and Napue v. Illinois, 360
U.S. 264 (1959). In Napue, the Supreme Court held that a "State may not
knowingly use false evidence, including false testimony, to obtain a
tainted conviction." Id. at 269 (emphasis added). There is no evidence in
the record that the Government knew that Turner was lying when she tes-
tified before the grand jury, and once the Government discovered the
perjury, it provided the defense with the supplemental discovery regard-
ing the perjury. Furthermore, the Government did not call Turner as a
witness at trial. Thus, there was no violation of Napue, and as discussed
above, the Government’s disclosure was sufficient to satisfy Brady.
10                           VINSON v. TRUE
tor at a time when Vinson was at work, a statement that conflicts with
one Hunter made in an affidavit submitted in the state habeas pro-
ceedings in which she claimed she never saw Vinson again after the
time of the crime. Vinson also points to a statement made in an affida-
vit not submitted until the federal habeas proceedings in which Hunter
claimed to have seen the perpetrator at a time that Vinson was undis-
putedly in police custody, and in which she contended the prosecution
threatened her into testifying. Vinson further claims Brady error from
the Government’s failure to disclose that there was a pre-existing rela-
tionship between Hunter and Turner, and that the second eye-witness,
Janice Green, stated that she did not know whether she would recog-
nize the perpetrator if she saw him again.

   The Supreme Court of Virginia concluded that even if the state-
ment in the handwritten notes regarding the second sighting of the
perpetrator was made by Hunter, it was not material since, given the
substantial evidence against Vinson, there was "no reasonable proba-
bility that had the [handwritten] notes been disclosed the result of
Vinson’s trial would have been different." The court also explained
that there was no evidence that the Government knew of the relation-
ship between Hunter and Turner, and in any event, it was immaterial.
And it further found that, even assuming Green’s statement could
have been used for impeachment, it too was not material.

   Again, AEDPA governs our review of the conclusions of the state
court as to the materiality of the handwritten statement and the rela-
tionship between Hunter and Turner, and whether the presence of
substantial physical and forensic evidence demonstrating Vinson’s
guilt weighed against the materiality of the suppressed evidence. In
particular, the record reveals that the Government presented evidence
of blood on Vinson’s shorts matching the DNA of the victim, Vin-
son’s fingerprints on the car in which the victim was abducted and in
the house where the victim’s body was found, and eyewitness testi-
mony identifying Vinson as the man who abducted the victim and as
the person who pulled a board off of the abandoned house and
dragged something heavy inside. Given this evidence,4 we can only
  4
    This evidence also forecloses Vinson’s claims that he is entitled to a
mandatory evidentiary hearing regarding the conflicting affidavits pre-
pared by Hunter. Vinson simply cannot show the required actual preju-
dice in view of the substantial evidence presented at trial. See Keeney,
504 U.S. at 11-12.
                            VINSON v. TRUE                           11
conclude that the state court’s adjudication that the withheld evidence
was not material is not contrary to or an unreasonable application of
Brady, and that the additional statements contained in Hunter’s fed-
eral habeas affidavit are insufficient to demonstrate a reasonable
probability of a different result.

   Vinson’s final Brady contention is that the materiality analysis con-
ducted by the state court was flawed. He argues that the cumulative
effect of the exculpatory evidence suppressed by the Government
caused actual prejudice and that habeas relief is therefore required
under Kyles v. Whitley, 514 U.S. 419 (1995). To satisfy Kyles, Vinson
must show that, considering all of the suppressed evidence, there is
a reasonable probability that the outcome of the trial would have
been different. Id. at 434. In light of the strength of the evidence in
this case, Vinson cannot meet this burden. The cumulative effect of
all of the undisclosed exculpatory or impeaching evidence simply
cannot satisfy the required showing of a reasonable probability of a
different result. See Strickler, 527 U.S. at 291-96 (denying relief
where, in light of the "considerable forensic and other physical evi-
dence linking petitioner to the crime," petitioner did not show a rea-
sonable probability of a different outcome had the suppressed
evidence been disclosed). Thus, because Vinson has shown neither
materiality nor actual prejudice, his final Brady claim also fails.

                                  V.

   For the foregoing reasons, the judgment of the district court deny-
ing habeas corpus relief is

                                                          AFFIRMED.
