John Ashley Brown, who is sentenced by the state of Louisiana to die, appeals the district court’s dismissal of his petition for a writ of habeas corpus under 28 U.S.C. § 2254. Brown insists that his conviction and death sentence are rendered unconstitutional by a list of alleged errors, including prosecutorial misconduct, ineffective assistance of counsel, and various defects in the jury instructions. Brown’s most serious contention is that the jury’s instruction on the “reasonable doubt” standard contained constitutional error. After a careful review of our precedent on this subject, we conclude that the district court did not err in rejecting this allegation and the other arguments that Brown makes.
I
On September 7,1984, Mr. and Mrs. Omer Laughlin were returning to their parked car after dinner at a New Orleans restaurant. Brown exited a nearby vehicle and confronted the Laughlins. Brown pushed the couple against their car and demanded money from Mr. Laughlin. As Mr. Laughlin handed over his wallet, Mrs. Laughlin screamed and ran back toward the restaurant. When Mrs. Laughlin returned shortly thereafter, Mr. Laughlin was dead. He had been stabbed 13 times.
Mrs. Laughlin gave the police a description of Brown, and also of the vehicle he had been sitting in before the attack. Mrs. Laughlin told police that a woman with dark hair had been driving the car. A short time later, an off-duty police officer, who had heard the crime reported on his police radio, noticed the ear as it pulled into a service station. After watching Brown washing his hands at a water hose, the officer apprehended Brown and his companion, Anna Hardeman. The officer observed blood, scratches and other marks on Brown’s forearms, and blood on Brown’s feet. A New Orleans Shopper’s card belonging to Omer Laughlin was visible on the floor of the car. Mr. Laughlin’s wallet and the murder weapon, a Bowie knife, were later found in the car. Mrs. Laughlin identified Brown from line-up photographs as the man who had assaulted her husband.
II
On September 20, Brown and Hardeman were indicted for first degree murder. *747 Hardeman entered into an agreement to plead guilty to a lesser charge of accessory after the fact. In April 1985, Hardeman’s counsel filed a motion concerning Harde-man’s right to a speedy trial, in an apparent attempt to get Hardeman released pending Brown’s trial. At a hearing on the motion, the prosecutor stated that Hardeman was “no longer cooperating with the state’s prosecution” and that any prior plea bargaining agreement was “no longer in effect.” Brown’s trial began before a jury on June 13. On the first day, the charges against Harde-man were severed, and the prosecutor stated that Hardeman would be tried separately.
During the guilt phase of the trial, Brown did not call any witnesses to testify on his behalf. He conceded that he had committed the acts in question, but argued- that he lacked the requisite intent to be convicted of first degree murder, claiming intoxication. The jury found Brown guilty of the premeditated murder of Omer Laughlin. A penalty phase to determine Brown’s sentence immediately followed. During the penalty phase, Brown argued that he should not be sentenced to death because his actions were partly attributable to his intoxication on the night he attacked Laughlin, his longstanding drug addiction, and his generally underprivileged childhood.
Brown called several witnesses during the penalty phase. Brown’s mother testified to Brown’s impoverished childhood and his early drug problems. Brown’s sister similarly testified to Brown’s childhood problems. Brown’s sister also stated that Brown was a heavy drug user in 1984, that he took drugs intravenously, and that he behaved strangely when he was using drugs. In 1984, the sister indicated, Brown was regularly using Man-dex (a bootleg quaalude), cocaine, and heroin. Brown presented expert testimony concerning the effects of his drug use.
Brown also called Hardeman to testify on his behalf during the penalty hearing. Hardeman took the stand, but after a few preliminary questions, the prosecutor interrupted the examination and requested that the court determine whether Hardeman had consulted with her attorney concerning her Fifth Amendment rights. At this point, Hardeman had not yet pled guilty, although she later did so under a plea bargaining agreement. Hardeman’s testimony was suspended, and the court summoned Harde-man’s attorney, who advised her to exercise her right against self-incrimination. When Hardeman resumed the stand, the court permitted her to invoke the Fifth Amendment over Brown’s objection.
The prosecution contested Brown’s claim that he was addicted to drugs. During cross-examination, the prosecutor elicited a concession from Brown’s expert that Brown showed no physical signs of intravenous drug use. The prosecution called its own psychiatrist who testified that Brown did not have track marks, a scarring caused by intravenous drug use, and that Brown’s prison records following his arrest did not reveal signs of physical withdrawal.
After deliberating, the jury unanimously decided that Brown should be sentenced to death. The jury found two statutory aggravating factors: (1) the murder was committed during the perpetration of an armed robbery, and (2) the offense was committed in an especially heinous, atrocious, and cruel manner.
Brown appealed his conviction and sentence to the Louisiana Supreme Court, which affirmed.
State v. Brown,
After an initial dismissal for incomplete exhaustion and an unsuccessful return to state court, Brown refiled his federal applica
*748
tion for habeas relief and was granted a stay of execution. The district court reviewed Brown’s twenty-two claims for relief in an exhaustive opinion, concluding that Brown’s application failed to demonstrate any constitutional defect in his conviction or sentence.
Brown v. Cain,
Ill
Brown raises three contentions that merit analysis our consideration. First, Brown argues that certain acts of the prosecution amount to prosecutorial misconduct that materially affected the outcome of the trial. Second, Brown insists that he was denied effective assistance of counsel. Third, Brown argues that the jury instruction on reasonable doubt was constitutionally defective. 1
Before addressing Brown’s arguments, we must examine the requirements imposed upon us by the recently enacted the Antiterrorism and Effective Death Penalty Act of 1996 (the “AEDPA”), Pub.L. No. 104-132, 110 Stat. 1214 (1996), which was signed into law by the President on April 24, 1996. The AEDPA substantially amends the federal habeas corpus provisions of Title 28. Two changes, in particular, are important to Brown’s appeal: the requirement that a habeas petitioner obtain a “certificate of appeal-ability” (“COA”), and the deferential standard of review imposed upon the federal courts when reviewing claims adjudicated on the merits in a state proceeding.
In
Drinkard v. Johnson,
In
Landgraf,
the Supreme Court indicated that “changes in procedural rules may often be applied in suits arising before their enactment without raising concerns about retroactivity” because procedural rules regulate “secondary” rather than “primary” conduct.
In
Drinkard,
we concluded that because the standard for issuing a COA under the AEDPA required the same showing as the standard under which CPCs were previously issued, no retroactivity issue was actually raised: the difference was simply one of nomenclature.
Drinkard,
More importantly for our purposes, the AEDPA amended 28 U.S.C. § 2254, clarifying the level of deference that a federal court must give to the prior judgments rendered by a state court on the merits of a habeas petitioner’s claims:
(d) An application for a writ of habeas corpus on behalf of a person in custody pursuant to the judgment of a State court shall not be granted with respect to any claim that was adjudicated on the merits in State court proceedings unless the adjudication of the claim—
(1) resulted in a decision that was contrary to, or involved an unreasonable application of, clearly established Federal law, as determined by the Supreme Court of the United States; or
(2) resulted in a decision that was based upon an unreasonable determination of the facts in light of the evidence presented in the State court proceeding.
AEDPA, § 104(3) (to be codified at 28 U.S.C. § 2254(d)) (emphasis added). In
Drinkard,
we interpreted the second clause of subsection (d)(1) to apply to challenged applications of law to fact. For such claims, we concluded, the amended provision permits federal court relief “only when it can be said that reasonable jurists considering the question would be of one view that the state court ruling was incorrect.”
Id.,
A
Brown raises three charges of “prosecuto-rial misconduct.” Brown argues that (1) the prosecution improperly manipulated Harde-man to prevent her from testifying on Brown’s behalf concerning his drug addiction and drug use on the night in question, (2) the prosecution withheld exculpatory evidence subject to disclosure, and (3) the prosecution improperly “gave a false impression” to the jury by disputing Brown’s claims of intoxication and drug addiction.
(1)
A prosecutor may not intimidate a witness into invoking the Fifth Amendment in order to interfere with a criminal defendant’s right to compulsory process.
United States v. Whittington,
During Brown’s entire trial, Hardeman remained under indictment for first degree murder, and she had not yet pled to this or any other charge. In Brown’s direct appeal, the Louisiana Supreme Court concluded that “[cjlearly she had reasonable cause to apprehend danger from direct answers concerning her whereabouts and contacts with Brown on the day of the murder.”
State v.
*750
Brown,
In Brown’s post-conviction proceedings, the state trial court considered and rejected this argument as a factual matter. During Brown’s post-conviction evidentiary hearing, Hardeman’s attorney testified that he believed there was a deal in place before Brown’s trial, but still advised Hardeman to take the Fifth out of caution. The state court rejected this statement, stating that “[t]he fact that Mr. Meyer, counsel for Ms. Hardeman, advised Ms. Hardeman to invoke her Fifth Amendment privilege at the trial of petitioner leads this Court to believe that he had grave doubts about the enforceability of any plea bargain agreement.” State ex rel. Brown v. Whitley, No. 303-750 (La.Dist.Ct., Orleans Parish, August 9, 1993) (unpublished). The court further noted the prosecutor’s statements at Hardeman’s speedy trial motion hearing, and the lack of any evidence in the record that a plea bargain agreement existed. Id.
The district court deferred to the state court’s conclusions on this disputed factual issue, as must we. The state court was required to assess the credibility of the witnesses who testified at Brown’s evidentiary hearing, and we will not dispute that court’s conclusions. We cannot say that the state court’s factual determination was “unreasonable,” and Brown therefore fails to make the showing required for relief under the amended § 2254(d).
(2)
Brown further cites “prosecutorial misconduct” in the prosecution’s failure to turn over “exculpatory evidence” of Brown’s intoxication and drug abuse history, in violation of
Brady v. Maryland,
The only evidence that arguably was withheld improperly under Brady was the statement of the servicé station attendant, Edward White, Jr., who stated that Brown appeared “kinda high” and that Brown’s speech was somewhat slurred. Brown insists that this statement is critical “non-specific statutory mitigating evidence” that would have been relevant to the penalty phase. As the district court observed, however, White’s statement also indicates that Brown specifically requested permission to use the station’s water hose, and that Brown evaded White’s inquiries concerning why Brown was covered with blood. As such, whether White’s statement was exculpatory or mitigating is open very much to question.
On post-conviction review, the state trial court held evidentiary hearings and reviewed the district attorney’s file — containing White’s statement — to determine whether Brady material was withheld. The court then rejected Brown’s Brady challenges. Whether evidence must be produced under Brady presents a mixed question of law and fact that was adjudicated on the merits by the state court, and its determination that no Brady violation occurred was not “an unreasonable application of clearly established federal law.”
The statement was not clearly exculpatory, and neither the Supreme Court nor this court has clearly held that statements of individuals known by the defense to have personal knowledge of relevant events must be delivered under
Brady,
where the defense is equally free to conduct an interview.
See, e.g., United States v. Fogg,
(3)
Finally, Brown argues that “prosecu-torial misconduct” violated his constitutional rights because the government knowingly gave the jury a false impression that there was no evidence to substantiate Appellant’s addiction to drugs and intoxication. Brown focuses on the prosecution’s examination of the medical experts, where the prosecution elicited testimony that Brown did not have track marks and had not experienced withdrawal following his arrest. Brown insists this was unconstitutionally misleading because the examinations (for track marks) did not take place until months after his arrest. Brown ignores the review of his records back to the time of his arrest, and does not indicate why any “misleading” impression was not corrected on cross or redirect examination. Brown’s allegations of misconduct in this respect clearly fail. Brown’s addiction and intoxication were centrally disputed issues, and the prosecution was not obligated to accept as true Brown’s claim that he was intoxicated based upon the statements of Brown and Hardeman.
B
Brown next contends that his conviction and sentence are unconstitutional because he was denied effective assistance of counsel. Specifically, Brown argues that he was denied effective counsel because (1) his counsel failed adequately to investigate his background, including school, medical and juvenile records, and to interview additional acquaintances and employers, (2) counsel failed to deliver such records to his psychiatric expert, and (3) counsel failed to retain a toxicologist as an expert witness.
Ineffective assistance of counsel claims are analyzed under the two-prong test of
Strickland v. Washington,
Both the state trial court in Brown’s post-conviction proceedings and the district court below considered Brown’s arguments at length and found them unavailing. Both courts found that Brown’s attorneys’ investigation was not deficient, and that additional testimony concerning Brown’s drug use and deprived past would simply have been cumulative to the testimony of Brown’s mother and sister. The state court specifically found that this alleged deficiency “fails to rise to the level of Strickland.” State ex rel Brown v. Whitley, No. 303-750 (La.Dist.Ct., Orleans Parish, August 9, 1993) (unpublished). We agree with this conclusion.
Brown attempts to substantiate his argument that his psychiatric expert was inadequately educated by pointing to the testimony of Dr. Alec Whyte during the post-conviction evidentiary hearing in state court. Dr. Whyte essentially testified that Brown suffered from certain mental disorders that were not revealed in expert testimony at trial. , Brown suggests that his trial expert must have been inadequately educated on his background, or he, too, would have reached the same conclusion. The state court, however, dismissed Whyte’s testimony, observing that Whyte was the only expert among five retained by Brown who concluded that Brown suf *752 fered from the identified disorders. Id. This evidence is simply inadequate to establish a constitutional violation under Strickland.
Brown’s argument that counsel was constitutionally ineffective by failing to retain a toxicologist — particularly at a time when toxicologists were not commonly retained for criminal trials — is unavailing. As the state court correctly concluded, neither the Sixth Amendment nor Strickland demanded that Brown’s counsel retain an expert with the label “toxicologist.” Id.
All of Brown’s “ineffective assistance” issues involve the application of existing law to the facts of Brown’s ease. His arguments were presented fully to the state court during his post-conviction proceeding, and the court adjudicated his claims on the merits. With respect to each argument raised here, the state court specifically found that the alleged deficiency did not rise to the level of a Strickland violation. Wé cannot say that the state court’s considered judgment was based upon an unreasonable application of clearly established federal law — in fact, we find it was unquestionably correct.
C
We turn now to Brown’s most serious contention: that the trial court incorrectly instructed the jury on the “reasonable doubt” standard. Brown argues that the reasonable doubt instruction was unconstitutional under the Supreme Court’s decision in
Cage v. Louisiana,
(1)
Once a criminal defendant’s conviction has been affirmed in the state appeals process, and no additional appeals may be taken, the conviction is “final.” Without a strong showing of error, the conviction must be considered to have been fully and fairly adjudged. The writ of habeas corpus, which allows a court to vacate a conviction after it has become final, serves a unique and limited purpose. As the Supreme Court explained in
Teague v. Lane,
the writ ensures the fundamental fairness of criminal proceedings by acting as “a necessary additional incentive for trial and appellate courts throughout the land to conduct their proceedings in a manner consistent with established constitutional standards.”
The Court in
Teague
reiterated that the purpose of the writ is satisfied if habeas review determines that the conviction rests upon a correct application of constitutional law at the time the conviction became final.
Id.,
Cage
was decided in 1990,
after
the Louisiana Supreme Court had affirmed Brown’s conviction in an extensive and reasoned opinion. Brown’s access to federal habeas relief on
Cage
grounds is therefore controlled by
Teague.
In
Skelton v. Whitley,
Brown argues that
Skelton
was implicitly overruled by the Supreme Court’s subsequent decision in
Sullivan v. Louisiana,
Brown argues that the Court’s holding in
Sullivan
“directly undermines” the analysis in
Skelton,
which had concluded that
Cage
error was not of a “structural” nature. Brown’s argument, however, has already been rejected by this court. In
Smith v. Stalder,
No. 93-3683,
Although
Smith
was an unpublished decision, we are bound by its holding. See Local Rule 47.5.3 (“Unpublished opinions issued before January 1, 1996 are precedent”). A panel is not at liberty to disagree with the decision of a prior panel. Absent action by the Supreme Court, any error Brown sees in
Smith
may be corrected only by this court sitting en banc.
FDIC v. Dawson,
(2)
Although we conclude that, under Fifth Circuit precedent, Teague bars the consideration of Brown’s Cage challenge on collateral review, we are persuaded to consider the federal district court’s alternate ground of dismissal, which was not addressed by the state courts: that Brown failed to demonstrate that the jury instruction was unconstitutional under Cage. We agrée. 3
In Cage, the U.S. Supreme Court concluded that a Louisiana jury instruction on reasonable doubt was constitutionally defective because it improperly raised the degree of “doubt” that would demand acquittal in a criminal trial to something more than “reasonable” doubt. The challenged instruction in Cage read:
If you entertain a reasonable doubt as to any fact or element necessary to constitute the defendant’s guilt, it is your duty to give him the benefit of that doubt and return a verdict of not guilty. Even where the evidence demonstrates a probability of guilt, if it does not establish such guilt beyond a reasonable doubt, you must acquit the accused. This doubt, however, must be a reasonable one; that is one that is founded upon a real tangible substantial basis and not upon mere caprice and con-jectüíe. It must be such doubt as would give rise to a grave uncertainty, raised in your mind by reasons of the unsatisfactory character of the evidence of lack thereof. *754 A reasonable doubt is not a mere possible doubt. It is an actual substantial doubt. It is a doubt that a reasonable man can seriously entertain. What is required is not an absolute or mathematical certainty, but a moral certainty.
Brown argues that the reasonable doubt instruction in his ease was similarly unconstitutional. During Brown’s trial, the jury was instructed, in relevant part, that:
If you entertain a reasonable doubt as to any fact or element necessary to constitute the guilt of the defendant, it is your sworn duty to give him the benefit of the doubt and return a verdict of not guilty. This doubt, however, must be a reasonable one, that is, one founded upon a real, tangible, substantial basis and not upon mere caprice, fancy, or conjecture. It must be such a doubt as would give rise to a grave •uncertainty raised in your mind by the unsatisfactory character of the evidence. Likewise, if the State has proved the guilt of the defendant to your satisfaction and beyond a reasonable doubt, it is your duty to return a verdict of guilty.
Brown argues that because his reasonable doubt instruction contains one of the phrases, i.e., a reference to “grave uncertainty,” that the Supreme Court scrutinized in finding the Cage instruction unconstitutional, his instruction must also be declared unconstitutional. We disagree.
The Supreme Court determined that the Cage instruction was unconstitutional after it had examined the instruction as a whole, which is the general rule applied in reviewing a challenged jury instruction. We will similarly examine Brown’s jury charge as a whole in order to determine whether it is unconstitutional under the reasoning of Cage.
Although Brown’s instruction does contain an identical “grave uncertainty” comment, the trial court in Brown’s case clearly did not equate “reasonable doubt” with “actual substantial doubt.” The instruction employs the “grave uncertainty” comment in reference to an admonition that reasonable doubt itself should be based upon the evidence or lack thereof: “... upon a real, substantial basis and not upon mere caprice, fancy, or conjecture ... [i]t must be such doubt as would give rise to a grave uncertainty raised in your mind by the unsatisfactory character of the evidence.” (Emphasis added). Furthermore, the court never suggested that the jury might convict on the basis of a “moral certainty.” In short, the trial court’s charge to the jury includes only one of the questionable phrases challenged in Cage, while the surrounding text of the charge is unobjectionable and repeatedly reiterates that the standard is “reasonable doubt,” and that verdict must be reached upon the evidence alone. 4
*755
Cage
found the connections between the three challenged phrases critical: “[w]hen those statements
are then considered with the reference to ‘moral certainty,’ rather than evidentiary certainty,
it becomes clear that a reasonable juror could have interpreted the instruction to allow a finding of guilt based upon a degree of proof below that required by the Due Process Clause.”
Considered in its entirety, the instruction in Cage appeared to create a downward swing in the prosecution’s burden of proof: the instruction began appropriately with “reasonable” doubt, moved to “grave uncertainty,” and then to “substantial” doubt, and concluded by suggesting that the jury could convict on the basis of a “moral certainty” rather than an evidentiary certainty. The challenged portion of Brown’s jury charge, by contrast, begins and ends with “reasonable” doubt, and indicates clearly that the State must prove guilt beyond a reasonable doubt — with no suggestion that a “moral certainty” might suffice in the absence of evidentiary proof. We also note that, later in the charge, the jury was reminded of the severity of the State’s burden with the admonition that Brown should not be convicted “unless the facts proved by the evidence exclude every reasonable hypothesis of his innocence.” Thus, there is a vast difference between the charge given in the case before us and the charge given in Cage.
Furthermore, the standard of appellate review applied by the Court in
Cage
has been modified by the Court’s decision in
Estelle v. McGuire,
IV
In conclusion, Brown has failed to establish that his conviction and sentence are unconstitutional. His various claims have been fully and fairly adjudicated both in the Louisiana state courts and by the district court below. The judgment of the state court concerning Brown’s allegations was neither “contrary to” nor “involved an unreasonable application of’ clearly established federal law. Nor was the state court’s decision “based on an unreason *756 able interpretation of the facts.” Brown’s petition for habeas relief under 28 U.S.C. § 2254 therefore fails. We AFFIRM the judgment of the district court, and hereby VACATE the stay of execution granted pending appeal.
AFFIRMED; stay VACATED.
Notes
. Brown raises a list of additional issues not addressed at oral argument: that his sentence was unreliable; that he was denied effective assistance of appellate counsel; that the verdict form's use of "recommends” rather than "determines” violated his Eighth Amendment rights; that including the word "unanimous” on the life sentence verdict form but not on the death sentence form violated the Sixth, Eighth, and Fourteenth Amendments; and that the jury was inadequately instructed on the consideration of mitigating evidence. Having reviewed the record, the parties’ briefs, and the reasoned opinion of the district court, we find these issues to be without merit.
. As we noted in Drinkard, there is an apparent discrepancy between the amended § 2253 and the amended version of Rule 22(b) of the Federal Rules of Appellate Procedure, which appears to allow a COA to be issued either by a district or circuit judge. Drinkard, 97 F.3d at 755-56 n. 4.
. We need not address whether the AEDPA's deferential standard applies to
alternative
grounds of decision that the state courts did not reach in rejecting a habeas petitioner’s claim for relief, because we find that Brown's argument that his reasonable doubt instruction was unconstitutional fails regardless of the standard of review we apply. We note that the Seventh Circuit has determined that the AEDPA’s deferential standard
would
apply,
Lindh v. Murphy,
. The instruction was insistent in its repetitious description of the State’s burden as proof beyond a reasonable doubt, and also reminded the jurors at several points that they could base their verdict only upon the evidence presented:
Now, a person accused of a crime is presumed by our law to be innocent until each element of the crime necessary to constitute his guilt is proven beyond a reasonable doubt. It is the duty of the jury in considering and applying to that evidence the law as given by the Court to give the defendant the benefit of every reasonable doubt arising out of the evidence or lack of evidence in the case. It is the duty of the jury if not convinced of the guilt of the defendant beyond a reasonable doubt to find him not guilty. The defendant is not required to prove his innocence, but may rest upon the presumption of innocence until it is overthrown by positive, affirmative proof offered by the State. The burden, therefore, is upon the State to establish to your satisfaction and beyond a reasonable doubt, the guilt of the defendant as to the crime charged. If you entertain a reasonable doubt as to any fact or element necessary to constitute the guilt of the defendant, it is your sworn duty to give him the benefit of the doubt and return a verdict of not guilty. This doubt, however, must be a reasonable one, that is, one founded upon a real, *755 tangible, substantial basis and not upon mere caprice, fancy, or conjecture. It must be such a doubt as would give rise to a grave uncertainly raised in your mind by the unsatisfactory character of the evidence. Likewise, if the State has proved the guilt of the defendant to your satisfaction and beyond a reasonable doubt, it is your duty to return a verdict of guilty ... You are to find from the evidence which facts have been proved and which facts have not been proved ... Evidence includes sworn testimony of witnesses, exhibits admitted into the record, and facts which may have been stipulated to by the attorneys for the State and the defense. You cannot consider as evidence any statements made by the lawyers during the trial. You cannot go beyond the evidence just referred to to convict the defendant of the crime charged.