CARL E. STEWART, Circuit Judge:
Petitioner-Appellant, Gary Eugene Big-by (“Bigby”), appeals the district court’s denial of his Petition for Writ of Habeas Corpus regarding his claim that, by declining to recuse himself after Bigby assaulted him, the trial judge denied Bigby his constitutional right to due process. Prominent among other claims raised by Bigby is his Penry claim that punishment phase jury instructions prevented the jury from acting upon mitigating evidence submitted in his behalf. For the reasons assigned herein, we affirm the conviction, reverse the district court’s denial of a COA on Bigby’s Penry claim, grant the COA, vacate Bigby’s sentence, and remand to the district court with instructions.
FACTUAL AND PROCEDURAL HISTORY
During the early morning hours of December 24, 1987, Grace Kehler returned from work to the trailer home she shared with Michael Trekell and their infant son, Jayson Kehler. Upon entering the trailer, Kehler found Michael Trekell’s body on the kitchen floor. Initially thinking Tre-kell was unconscious, Kehler phoned “9-1-1” for assistance. In response to questions asked by the 9-1-1 operator, Kehler remembered that Trekell was caring for Jayson. She then began looking for her son and discovered him lying dead in a face down position in a sink full of water. When questioned as to possible suspects by the police, Kehler implicated Bigby. She noted that there were three steaks upon the table that were not there when she left for work and recalled frequent visits by Bigby at the residence.
Arlington Police Officer James Green-well arrived at the scene at approximately 5:10 a.m. to perform various duties as a crime scene investigator. He took photos, developed a diagram of the layout of the trailer, performed a gunshot residue test on both the infant and Trekell, and obtained postmortem fingerprints from Tre-kell. Officer Greenwell also collected beer cans and a wine cooler bottle from the trash which he thereafter had checked for fingerprints.
Dr. Charles Harvey, Deputy Tarrant County Medical Examiner, performed the autopsies. Dr. Harvey ruled that the manner of both deaths was homicide. He determined that the cause of Trekell’s death was craniocerebral trauma due to a gunshot wound by a .357 Magnum revolver. He determined that the infant died as the result of drowning.
On December 26, 1987, Fort Worth Police Detective Larry Ansley was summoned to act as a negotiator to defuse a man’s standoff with police at a Tarrant County motel. The person inside the motel room was Bigby. Shortly after Detective Ansley made contact, Bigby cracked the door and said to the detective, “I know that I am guilty and so do you.” Bigby surrendered without incident, and was taken to Fort Worth’s John Peter Smith Hospital.
The following morning, Fort Worth Police Homicide Detective Curtis D. Brannan interviewed Bigby after advising him of his Miranda rights. At about 3:00 a.m. on December 27, 1987, Bigby provided the police a written statement in which he confessed to killing Trekell and the infant. The fingerprints found on the wine cooler [265]*265bottle at the crime scene were later matched to the fingerprints of Bigby.
Bigby was tried for capital murder. During a trial recess, Bigby approached the unoccupied bench of Judge Don Leonard (“Judge Leonard”), found a gun, and took it. In an apparent attempt to escape, Bigby proceeded to Judge Leonard’s chambers and pointed the gun to the judge’s head stating: “Let’s go.” He was ultimately subdued. Bigby’s counsel then moved for a mistrial, which the judge denied.
In response to Bigby’s motion for Judge Leonard’s recusal, the matter was referred to the presiding administrative judge, who held a hearing. During the hearing, Judge Leonard testified that Bigby’s assault had not prejudiced or biased him toward the defendant. After cross-examination, the presiding judge concluded that Judge Leonard did not have to recuse himself, and the trial continued.
Upon the defense resting after the guilt/innocence phase of trial, Judge Leonard allowed the state, in its rebuttal, to introduce testimony about Bigby’s attempted escape as evidence of his “consciousness of guilt” for the Trekell murders. After the trial was completed, a jury ultimately rejected Bigby’s asserted defense of insanity. Furthermore, they found him guilty of the offense of capital murder and imposed the death penalty. The trial court entered judgment on March 25, 1991, in conformity therewith.
The Texas Court of Criminal Appeals affirmed the conviction and death sentence on direct appeal, and the United States Supreme Court denied Bigby’s petition for a writ of certiorari. Bigby v. State, 892 S.W.2d 864 (Tex.Crim.App.1994), cert. denied, 515 U.S. 1162, 115 S.Ct. 2617, 132 L.Ed.2d 860 (1995). Bigby then filed a state application for writ of habeas corpus, which the Texas Court of Criminal Appeals denied. Ex parte Bigby, No. 34-970 (Tex.Crim.App. filed Feb. 4, 1998).
On August 10, 1998, court-appointed counsel then filed a federal Petition for Writ of Habeas Corpus in the United States District Court for the Northern District of Texas, Fort Worth Division. Adopting the findings of United States Magistrate Judge Charles Bleil, the district court denied Bigby’s Petition for Ha-beas Corpus on October 18, 1999. On December 7, 1999, however, the court granted Bigby a Certificate of Appealability (“COA”) on the sole question of “[wjhether Petitioner was denied the right to a trial presided over by a fair and impartial judge after he assaulted the state trial judge.” Thereafter, all issues in the petition were fully briefed and oral argument was held in November 2000. Because of developing case law regarding the Penry claim, i.e. Penry v. Johnson, 532 U.S. 782, 121 S.Ct. 1910, 1922, 150 L.Ed.2d 9 (2001) {Penry II) and Robertson v. Cockrell, 325 F.3d 243 (5th Cir.2003), the parties have filed comprehensive supplemental briefing. We now address the COA granted issue and Bigby’s remaining claims for which the district court did not grant a COA.
DISCUSSION
I. Standard of Review
To obtain a COA, a petitioner must demonstrate “that jurists of reason could disagree with the district court’s resolution of his constitutional claims or that jurists could conclude the issues presented are adequate to deserve encouragement to proceed further.” Miller-El v. Cockrell, 537 U.S. 322, 123 S.Ct. 1029, 1034, 154 L.Ed.2d 931 (2003). “Because the present case involves the death penalty, any doubts as to whether a COA should [be] issue[d] must be resolved in [the petitioner’s] fa[266]*266vor.” Hernandez v. Johnson, 213 F.3d 243, 248 (5th Cir.2000). When determining if a petitioner is entitled to a COA, we must apply the “deference scheme laid out in 28 U.S.C. § 2254(d).” Moore, 225 F.3d at 501. Under this scheme, “we review pure questions of law and mixed questions of law and fact under § 2254(d)(1), and review questions of fact under § 2254(d)(2), provided that the state court adjudicated the claim on the merits.” Id. at 501 (citation omitted).
Because Bigby’s federal petition for habeas review was filed in 1998, we review it under the standards articulated in the Antiterrorism and Effective Death Penalty Act (“AEDPA”). See 28 U.S.C. § 2254. ' Under that statute, a federal court may only grant a state prisoner’s application for a writ of habeas corpus if his incarceration was the product of a state court adjudication that “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[J” 28 U.S.C. § 2254(d)(1). “A decision is contrary to clearly established federal law ‘if the state court arrives at a conclusion opposite to that reached by [the Supreme Court] on a question of law or if the state court decides a case differently than [the] Court has on a set of materially indistinguishable facts.’” Gardner v. Johnson, 247 F.3d 551, 557 (5th Cir.2001)(alterations in original (quoting Williams v. Taylor, 529 U.S. 362, 413, 120 S.Ct. 1495, 146 L.Ed.2d 389 (2000)). “ ‘[I]f the state court identifies the correct governing legal principle ... but unreasonably applies the principle to the facts of the prisoner’s case[,]’ ” the court’s decision represents an unreasonable application of federal law. Id. (quoting Williams, 529 U.S. at 413, 120 S.Ct. 1495). We presume that a state court’s factual findings are correct and defer to them “unless they were based on an unreasonable determination of the facts in light of the evidence presented in the State court proceeding.” Id. (internal quotation and citation omitted); 28 U.S.C. § 2254(d)(2).
II. Due Process: Fair Tribunal
While this case involves novel yet disturbing facts, the fundamental underlying policies and law that these facts implicate are much less unique. Stated succinctly, the cornerstone of the American judicial system is the right to a fair and impartial process. See, e.g., Bracy v. Gramley, 520 U.S. 899, 117 S.Ct. 1793, 138 L.Ed.2d 97 (1997). Therefore, any judicial officer incapable of presiding in such a manner violates the due process rights of the party who suffers the resulting effects of that judicial officer’s bias. See id.
“The Due Process Clause of the Fourteenth Amendment establishes a constitutional floor, [however,] not a uniform standard.” Id. at 904, 117 S.Ct. 1793. This floor “clearly requires a ‘fair trial in a fair tribunal,’ before a judge with no actual bias against the defendant or interest in the outcome of his particular case.” Id. at 905, 117 S.Ct. 1793 (citation omitted). The crux of Bigby’s habeas corpus complaint is that his assault of Judge Leonard created an impermissible bias that ultimately violated Bigby’s clearly established constitutional right to a fair trial.
In response to Bigby’s claim, the district court adopted the magistrate judge’s Findings, Conclusions, and Recommendations and recognized that “bias by an adjudicator is not lightly established.” Valley v. Rapides Parish Sch. Bd., 118 F.3d 1047, 1052 (5th Cir.1997). This is true because, “[o]rdinarily, we presume that public officials have properly discharged their official duties.” Bracy, 520 U.S. at 909, 117 S.Ct. 1793 (internal quota[267]*267tions and citations omitted). As such, the district court reasoned that Bigby had the burden to overcome “two strong presumptions: (1) the presumption of honesty and integrity of the adjudicators; and (2) the presumption that those making decisions affecting the public are doing so in the public interest.” Valley, 118 F.3d at 1052.
We note that the United States Supreme Court has consistently enforced the basic right to due process and found that decision makers are constitutionally unacceptable when: (1) the decision maker has a direct personal, substantial, and pecuniary interest in the outcome of the case; (2) an adjudicator has been the target of personal abuse or criticism from the party before him; and (3) a judicial or quasi judicial decision maker has the dual role of investigating and adjudicating disputes and complaints. Id.1 To demonstrate such a due process violation and secure relief based thereon, Bigby was required to establish that a genuine question exists concerning Judge Leonard’s impartiality. See Liteky v. United States, 510 U.S. 540, 552, 114 S.Ct. 1147, 127 L.Ed.2d 474 (1994).2 Moreover, adjudication before a biased trial judge falls within the “very limited class of cases” that represents a “structural” error subject to automatic reversal. Ned-er v. United States, 527 U.S. 1, 7-8, 119 S.Ct. 1827, 144 L.Ed.2d 35 (1999).
III. Recusal After a Party Attacks the Judge
Bigby’s assault of Judge Leonard and the due process violations alleged to have occurred on the subsequent failure to re-cuse him present a res nova issue within the Fifth Circuit. Nonetheless, persuasive authority from one of our sister circuits appears propitious to the instant inquiry. See Wilks v. Israel, 627 F.2d 32 (7th Cir. 1980).
In Wilks, the petitioner became agitated and angry with the judge and threw a stamping machine and microphone at him during a pretrial hearing. Id. at 36. When the petitioner was on the witness stand, but while the jury was not in the courtroom, he jumped from the chair and assaulted the trial judge. Id. While still outside of the jury’s presence, the judge stated, “I am going to say it for the record, he is going away for so long they are going to forget that they ever knew him, and I [268]*268want any reviewing court to know what my intentions are.” Id. When his emotions subsided, the judge recanted from this position stating that he had had over sixty jury trials in that year and that “this is just another defendant” as far as he was concerned. Id. The judge then proceeded to preside over the defendant’s trial. Id. at 36-37.
Discussing whether the trial judge’s refusal to recuse himself was in error, the court stated that “the petitioner must show that the refusal to recuse was a ‘fundamental defect which inherently result[ed] in a complete miscarriage of justice....’” Id. at 37 (quoting Hill v. United States, 368 U.S. 424, 428, 82 S.Ct. 468, 471, 7 L.Ed.2d 417 (1962)). The court further reasoned that while a trial judge could be expected to react adversely to such unruly conduct, “[a] petitioner’s deliberate attack on the trial judge calculated to disrupt the proceedings will not force a judge out of a case.” Id. (citing Mayberry v. Pennsylvania, 400 U.S. 455, 463, 91 S.Ct. 499, 504, 27 L,Ed.2d 532 (1971)). To conclude otherwise would implicitly sanction such attacks in desperate attempts by defendants to precipitate new trials before new judges, encourage unruly courtroom behavior, and “greatly disrupt judicial administration.” Id.
Thus, the Wilks court explicitly declined to adopt a per se rule based on the mere appearance of prejudice, opting instead to “examine the trial to ensure that the trial judge, despite having good cause for adverse feelings toward a defendant, has conducted a fair trial.” Id. at 37 n. 6. The central criterion the Wilks court utilized in determining whether the trial judge had conducted a fair trial was whether the trial judge’s rulings presented indicia of a bias against the defendant. Id. at 37. Finding, from a review of the record, that “the [trial] court’s rulings were appropriate and in no way reflected any animosity toward the petitioner,” the Wilks court concluded that “petitioner received a fair trial free from judicial prejudice.” Id.
We agree with the Seventh Circuit’s approach. A per se rule of recusal would lend itself to deliberate manipulation of the judicial system. Such an automatic rule would invite recusal motions from defendants whose sole purpose in attacking a judge or engaging in unruly behavior is either to manufacture constitutional due process violations or to delay trial proceedings. Therefore, contrary to petitioner’s request, we decline to presume prejudice on the part of the trial judge simply because of the fact of the attack, but rather must examine the record for indications of actual bias on the part of the trial judge.
Petitioner urges that the trial judge’s decision to allow evidence of petitioner’s attack on the judge, and his concomitant refusal to provide a limiting instruction restricting the jury’s consideration of the evidence to its bearing on petitioner’s state of mind, constitute indicia of the trial court’s bias. In determining whether the judge’s ruling on these matters indicated bias on his part, we first look to the precise nature of the evidence proffered, and then to the court’s stated basis, if any, for its decision to admit the evidence without a limiting instruction.
The state first proffered the testimony of Bailiff Tim M. Stallings (“Stallings”), who was present in the courtroom at the time of petitioner’s escape attempt. Stallings testified in relevant part as follows:
Q. During a break earlier this morning about 10:00 o’clock, where were you?
A. I was sitting at my desk over there.
[269]*269Q. Who was in the courtroom as you recall at that time?
A. The defendant, and I think you were.
Q. When you say “the defendant,” who are you talking about?
A. James Bigby, the gentleman at the end of the table there....
Q. The jury was not in the courtroom, were they?
A. No, sir....
Q. While you were seated -, what
did the defendant do?
A. He got up like he was going to get a drink of water and then—
Q. What happened at that point?
A. And he didn’t get any water and he started running behind the bench. I jumped up and started after him....
Q. What did he do?
A. He reached in and got to the Judge’s desk and started reaching for the drawer, and I drew my weapon.
Q. Did you say anything at that point?
A. I told him to stop again.
Q. Did he?
A. No. He pointed a gun at me....
Q. When you say “a gun,” what kind of gun are you talking about?
A. .38 Colt.
Q. Revolver?
A. Yes, sir.
Q. What did he do with that gun?
A. He pointed it towards me.
Q. What happened at that point?
A. I ducked down behind the clerk’s desk, and then I heard a noise, sounded like the Judge’s chair was moving. So I jumped up and saw him running, and then I came around by the court reporter’s desk and he pointed the gun at me again and I ducked, and by the time I could get back up, he had gone through the door into the corridor.
After the conclusion of Stallings’ testimony, the state called Bailiff Barbara Hackney (“Hackney”) to the stand. On direct examination, she testified as follows:
Q. How are you employed?
A. I’m employed by Judge Leonard as Grand Jury bailiff, Tarrant County.
Q. About 10:00 o’clock this morning were you in his office?
A. Yes, I was.
Q. Do you remember anybody else who was in the office?
A. Yes. A man came through the door to the right side of me with a gun in his hand.
Q. Do you see that person in the courtroom?
A. Yes, I do.... This man over here with a suit on and hair back.
Mr. Medlin: Your honor, may'the record reflect she has identified the Defendant?
THE COURT: It may so reflect
Q. Was Judge Leonard in the room?
A. Yes, he was....
Q. What did the person you identified do as he walked into the Judge’s room, office?
A. He walked into the room beside the desk.... He had a gun in his hand. He walked up about two steps toward the Judge ... and he pointed it at his head and said, “Let’s go, Judge.”
Q. What happened at that point?
A. At that point the Judge looked up at him and immediately jumped up out of his chair and grabbed the gun hand, slammed it up and back against the wall. They ended up [270]*270against the wall, and when they did I ran out looking for someone to help.
Q. Where did you see the person you identified point the gun at the Judge; at what part of the Judge did he point the gun?
A. He pointed it right at his head. He was standing over — the Judge was sitting and he was standing over him, and he had it right at his head.
Q. Are you talking about Judge Leonard seated just to your right?
A. Yes, sir. Judge Leonard was seated right in front of me.
In evaluating the potential effect of this evidence on the jury, we are persuaded that while admitting Bailiff Stallings’ testimony struck the appropriate balance between the competing concerns regarding introducing evidence of Bigby’s skullduggery, this delicate balance swung out of kilter when the prosecution proffered Bailiff Hackney’s testimony. Hackney’s testimony was prejudicial to the petitioner because of a jury’s typically high regard for a presiding judge and the probability that the jury in Bigby’s case came to identify with the judge during the course of the proceedings. See, e.g., Carolyn E. Demurest, Civility in the Courtroom from a Judge’s Perspective, 69 N.Y. St. B.J. 24, 25 (May/June 1997) (“[Jjurors usually identify with the judge who, like themselves, is meant to be impartial. A personal attack upon the judge is likely to turn the jury against the attacking attorney....”). Although admission of the evidence may have itself been a violation of petitioner’s due process rights, because of the potential that its admission deprived defendant of a fair trial, that is a separate question from whether the trial judge’s admission of the testimony, and corresponding failure to give a limiting instruction, constitute indi-cia of bias on the judge’s part. Because the trial court provided a basis for admission of the evidence grounded in established law, we cannot conclude that such is the case.
After the state announced that it intended to proffer testimony of Bigby’s attempted escape, defense counsel objected to the testimony on the basis that “the prejudicial nature of it highly outweighs the probative value,” and that it would deny Bigby “a fair trial.” The court overruled the objection, providing the following justification for its ruling:
The Court finds that the evidence tendered by the state concerning his attempted escape is admissible on the basis of guilt or innocence in trials of this State, and it may have some relevance to the jury if they consider it important of any planning he might have affecting his insanity. I don’t know if the jury thinks it’s important or not, but they will receive it.
When presented with this issue on direct appeal, the Texas Court of Criminal Appeals analyzed the admissibility of the attack evidence solely from an evidentiary standpoint. It reasoned that “[ejvidence of flight or escape is admissible as a circumstance from which an inference of guilt may be drawn,” and in Bigby’s case “the evidence of flight enhance[d] the State’s case.” Bigby v. State, 892 S.W.2d 864, 884 (Crim.App.1994). Thus, the Court of Criminal Appeals concluded that “the trial court’s ruling was within the ‘zone of reasonable disagreement’ ” and not clearly erroneous. Id.
In a subsequent application for state habeas corpus relief, Bigby asserted that Judge Leonard violated his due process rights by allowing evidence of his having assaulted the court. After deciding that a fact-finding hearing was unnecessary, the Criminal District Court characterized Big-by’s claim as a mere evidentiary challenge [271]*271that had been previously “raised and rejected by the Court of Criminal Appeals on direct appeal” and summarily concluded that Bigby “ha[d] failed to plead or prove that the issue rendered his conviction void.3 Upon review, the Texas Court of Criminal Appeals found Bigby’s due process argument similarly unavailing.4
By conflating Bigby’s due process and evidentiary claims, the Texas state courts erred in their analysis of the bias issue. While the admissibility of the attack evidence and the ability of the trial judge to act as a fair and impartial tribunal are separate questions, they are necessarily interrelated. If the trial judge had no obvious support for his ruling in the law, the decision would likely reveal an illicit predisposition- — the poisoned font from which the ruling sprang.
"While, in our opinion, the trial court erred in failing to quell the testimony regarding the attack before the jury heard Bailiff Hackney’s rendition of the petitioner’s taking the trial judge hostage and holding a gun to his head, we cannot conclude that this alone overrides the presumption of fairness on the trial judge’s part and compels a conclusion that structural error inhered in petitioner’s trial. The judge was not without a legal basis for his ruling, as under Texas law evidence of an escape is admissible if relevant. Burks v. State, 876 S.W.2d 877, 903 (Tex.Crim. App.1994). Although the trial court, as evidenced by its rulings, implicitly failed to recognize the prejudicial effect such evidence might have on the jury, he was not acting clearly outside the bounds of law or reason in a manner that would signal any bias toward the defendant. Thus, we conclude that the trial court’s decisions in regard to the attack evidence do not, by themselves, constitute indicia of bias sufficient to declare the trial tainted by structural error.
This conclusion does not end our due process inquiry, however. We must next take up the question whether, apart from the issue of the trial judge’s bias, the court’s admission of the attack evidence and failure to provide a limiting instruction deprived petitioner of a fair trial, due to the prejudicial nature of the evidence. “[W]hen a state court admits evidence that is ‘so unduly prejudicial that it renders the trial fundamentally unfair, the Due Process Clause of the Fourteenth Amendment provides a mechanism for relief.’ ” Dawson v. Delaware, 503 U.S. 159, 179, 112 S.Ct. 1093, 117 L.Ed.2d 309 (1992) (quoting Payne v. Tennessee, 501 U.S. 808, 825, 111 S.Ct. 2597, 115 L.Ed.2d 720 (1991)). In conducting this analysis, it is irrelevant whether the evidence was correctly admitted pursuant to state law. Estelle v. McGuire, 502 U.S. 62, 67-68, 112 S.Ct. 475, 116 L.Ed.2d 385 (1991). Rather, our sole inquiry is whether the admission [272]*272violated the Constitution. Id. at 68, 112 S.Ct. 475..
Whether admission of the attack evidence, coupled with the trial court’s refusal to provide a limiting instruction, constitute a violation of defendant’s due process rights is not the sole focus of our constitutional analysis. “Assuming arguendo that the admission of [the evidence] was constitutional error,” petitioner’s claim will still fail absent a showing “that the testimony had a ‘substantial and injurious effect or influence in determining the jury’s [] verdict.’” Janecka v. Cockrell, 301 F.3d 316, 328-29 (5th Cir.2002). Examining the evidence put forth during the guilt/innocence stage of Bigby’s trial, we find “it is highly improbable that the jury would have” reached a different verdict had the evidence been excluded, or had the trial judge given a limiting instruction. See id. The state presented overwhelming evidence that defendant committed the murders, including two confessions by defendant. It also elicited testimony from two psychiatric experts, including one who had been petitioner’s psychiatrist before his incarceration, that Bigby did not suffer from a severe mental disease or defect such that he could not tell or did not know his conduct was wrong. As the Court of Criminal Appeals concluded, “[w]hile several of appellant’s experts testified that appellant could not or did not know his conduct was wrong, several did testify that appellant knew his conduct was illegal.” Bigby, 892 S.W.2d at 877. Furthermore, Bigby’s statement to the police at the time of his arrest, that “I know I am guilty and so do you ... evinces an understanding by [Bigby] that he knew his conduct was illegal.” Id. We therefore conclude that, even if the prejudicial effect of the attack evidence was of a constitutional dimension, petitioner’s due process argument fails because he cannot establish that the evidence had a substantial or injurious effect or influence on the jury’s verdict at the guilt/innocence stage of the proceedings.
The effect of the attack evidence at the sentencing stage is more difficult. We decline to consider this question, however, because, as discussed below, we vacate petitioner’s sentence and remand this case for resentencing on the basis that the trial court committed reversible error in giving the “nullification instruction” to the jury during the sentencing proceedings.
IV. Bigby’s Additional Claims for Grant of COA
A. Unconstitutional Jury Instructions
In his application for COA, Bigby further argues that the district court’s jury instruction gave the jurors an option of nullifying mitigating circumstances and thus impinged his right to have an individualized assessment of the appropriateness of the death penalty in his case. According to Bigby, this violated Penry v. Ly-naugh, 492 U.S. 302, 109 S.Ct. 2934, 106 L.Ed.2d 256 (1989) (Penry I). The Texas Court of Criminal Appeals rejected this complaint when Bigby raised it on direct appeal. Bigby, 892 S.W.2d at 890. Relying on Roberts v. Louisiana, 428 U.S. 325, 335, 96 S.Ct. 3001, 3007, 49 L.Ed.2d 974 (1976), Bigby reiterates his nullification argument by claiming that there is an “element of capriciousness in making the jurors’ power to avoid the death penalty dependant on their willingness to accept [an] invitation” to render a false verdict.
A State’s capital punishment scheme must do two things to meet the requirements of the Eighth Amendment. First, it must “channel the discretion of the judge or jury to ensure that the death sentence is not meted out wantonly or freakishly.” Graham v. Collins, 506 U.S. [273]*273461, 468, 113 S.Ct. 892, 898, 122 L.Ed.2d 260 (1993). Second, it must confer sufficient discretion on the sentencing body to consider the character and record of the individual offender. Id. Thus, the relevant mitigating evidence cannot be placed beyond the effective reach of the jury. Id. at 475, 113 S.Ct. 892. “To grant relief on a Penry claim, we must determine (1) that the ... evidence was constitutionally relevant mitigating evidence, and, if so, (2) that the ... evidence was beyond the effective reach of the jury.” Madden v. Collins, 18 F.3d 304, 308 (5th Cir.1994).
We conclude that Bigby has demonstrated that reasonable jurists would find the district court’s assessment of his Penry claim debatable. See Miller-El, 123 S.Ct. at 1040. First, Bigby has established there exists evidence of constitutionally relevant mitigating evidence. In particular, Bigby has provided testimony that he suffers from chronic paranoid schizophrenia, an involuntary, permanent, and severe mental condition that contributed to his criminal actions consistent with the standard set forth in Robertson v. Cockrell, 325 F.3d 243 (5th Cir.2003). Second, the nullification instruction at issue in the instant case is similar to the nullification instruction that the Supreme Court rejected as unconstitutional in Penry I, rendering the constitutionally mitigating evidence out of the reach of the jurors during the punishment phase of Bigby’s trial. Thus, we reverse the district court’s denial of a COA on this issue and grant the COA. During the pendency of this appeal the Supreme Court handed down Penry II, 532 U.S. 782, 121 S.Ct. 1910, 1922, 150 L.Ed.2d 9 (2001) and the en banc court decided Robertson v. Cockrell, 325 F.3d 243 (5th Cir.2003). Because the post oral argument briefing has fully addressed these cases and because the evidentiary record is complete, we conclude that the merits of the COA Penry claim — that the nullification instruction during the sentencing phase of his trial was constitutionally defective — is ripe for decision.
1) Constitutionally Relevant Mitigating Evidence
This Circuit has created a two-part test that a defendant must prove in order to submit relevant evidence that he is less culpable for the crime he committed. The evidence presented must establish “(1) a uniquely severe permanent handicap[ ] with which the defendant was burdened through no fault of his own, and (2) that the criminal act was attributable to this severe permanent condition.” Davis v. Scott, 51 F.3d 457, 460-61 (5th Cir.1995) (internal quotation marks and citations omitted); see Robertson, 325 F.3d at 251 (“This formulation encompasses four principles found in Penry I: voluntariness, permanence, severity, and attribution.”).
During Bigby’s trial, Dr. James Grigson (“Dr.Grigson”), psychiatrist, was called to testify on Bigby’s behalf. Dr. Grigson stated that in his opinion, Bigby suffers from chronic paranoid schizophrenia. He testified that paranoid schizophrenia is one of the more serious and severe forms of mental illnesses. When asked to explain to the jury the effects of this disease, Dr. Grigson stated that usually individuals suffering from this mental condition “feel[] that people are plotting against them or doing things to hurt them.” He continued to clarify that schizophrenia means “that the individual is suffering from a psychosis where there is gross impairment in terms of interpersonal relationships ... and reality testing, meaning that they misperceive what is going on around them.” As a result, Dr. Grigson stated that this paranoid disorder manifests itself in psychotic delusional beliefs.
[274]*274Bigby’s trial counsel asked Dr. Grigson if Bigby had suffered from any delusions or psychotic beliefs. The physician responded in the affirmative. Specifically, he stated that at the time the murders occurred, Bigby suffered from delusions that Michael Trekell was involved in a conspiracy against him. In his opinion, Dr. Grigson testified that “at the time of the offense ... Bigby was suffering from [this] serious severe mental illness and was not aware of the difference between right and wrong.” Dr. Grigson concluded that there is no other explanation for Bigby’s actions other than the fact that he suffers from a mental illness.5 At the sentencing phase, Dr. Grigson reiterated his belief that Bigby suffers from chronic paranoid schizophrenia.
“[F]or evidence to have mitigating relevance to the special issues, there must be a nexus between the mitigating evidence and the criminal act.” Davis v. Scott, 51 F.3d at 460. In Davis, we determined that Davis’s evidence of paranoid schizophrenia did not rise to the level of constitutionally relevant mitigating evidence. Specifically, we found that if Davis in fact suffered from paranoid schizophrenia, he failed to submit any evidence linking his mental condition to the commission of the mur[275]*275ders. The holding in Davis, however, can be distinguished from the instant case.
Applying the requirements set out in Davis, it is clear that the evidence submitted by Bigby constitutes constitutionally relevant mitigating evidence. Paranoid Schizophrenia is a severe mental illness that is permanent and is not caused by any fault of the individuals suffering from the disease. Thus, as an individual suffering from this mental condition, Bigby has satisfied the first prong of the test. In regard to the second requirement, unlike in Davis, Bigby’s paranoid schizophrenia caused an insane delusion that there was a conspiracy for which at least one of his victims was a part of and, as a direct result of this delusion, Bigby committed the crimes for which he was convicted. Thus, Bigby has established a sufficient nexus between his mental illness and the murders.
2) Jury Instructions
We now turn to Bigby’s contention concerning the constitutionality of the jury instructions given by the district court judge at the sentencing phase. Bigby argues that the jury instructions impermissi-bly restricted the jury’s consideration of mitigating circumstances in violation of the Supreme Court’s decision in Penry I. In Penry I, the Court held that Penry’s Eighth Amendment rights were violated because the jury was inadequately charged with respect to mitigating evidence at Pen-ry’s sentencing hearing. At the conclusion of the hearing, the jury was instructed to answer three “special issues”: (1) whether the conduct that caused the death of the victim was committed deliberately and with a reasonable expectation that death would result; (2) whether there was a probability that the defendant would commit acts that would constitute a continuing threat to society; and (3) whether the conduct was an unreasonable response to any provocation by the victim. The Supreme Court held that none of these special issues were broad enough to allow the jury to consider and give effect to the mitigating evidence offered by Penry that he was mentally retarded and had been severely abused as a child.
On remand, Penry was again found guilty, and the state court instructed the jury to answer the same three special issues given at his first trial. The jury was also admonished that a “yes” answer to any of the special issues was warranted only if supported by the evidence “beyond a reasonable doubt,” while a “no” answer is appropriate only if there is a reasonable doubt that the answer to the special issues should be “yes.” In addition, the court also provided a “supplemental instruction” indicating that when the jury deliberated on the special issues, it was to consider mitigating issues, if any, presented by the evidence. The instruction provided in relevant part that “[the jury] must decide how much weight [the mitigating evidence] deserve[s], if any, and therefore, give effect and consideration to them in assessing the defendant’s personal culpability at the time [the jury] answers the special issues,” if the jury were to determine, “when giving effect to the mitigating evidence, if any, that a life sentence, as reflected by a negative finding to the issue under consideration, rather than a death sentence, is an appropriate response to the personal culpability of the defendant, a negative finding should be given to one of the special issues.” The verdict form contained only the text of the three special issues, however, and gave the jury the choice of only answering “yes” or “no.” The jury again answered all of the special issues “yes” and Penry was sentenced to the death penalty.
[276]*276In Penry II, the Supreme Court ruled that this supplemental instruction provided “an inadequate vehicle for the jury to make a reasoned moral response to Pen-ry’s mitigating evidence.” 532 U.S. 782, 121 S.Ct. 1910, 1922, 150 L.Ed.2d 9 (2001). Specifically, the Court again stated that the special issues were not broad enough to give effect to Penry’s mitigating evidence, and thus, held that the supplemental instruction was of no practical effect because the jury’s ability to give weight to Penry’s mitigating evidence was “still shackled and confined within the scope of the three special issues.” Id. at 1921 (internal quotation marks and citation omitted). The Supreme Court also noted that instructing the jury to answer the special issues “yes” only if supported by the evidence “beyond a reasonable doubt,” while at the same time instructing the jury to answer one or more of the special issues “no” in order to give effect to any mitigating evidence presented by Penry did not comport with reason and logic. It stated that in effect, the instruction allowed the jurors to change one or more “truthful ‘yes’ answers to an untruthful ‘no’ answer in order to avoid the death sentence for Penry.” Id. at 1922. Thus, if the jury desired to answer one or more of the special issues untruthfully to give credence to the mitigating evidence presented by Penry, they would have had to violate their oath to render a “true verdict.” Penry II, 532 U.S. at 800, 121 S.Ct. 1910 (citation omitted).
The special issues and supplemental instruction given at the conclusion of Bigby’s sentencing hearing are almost identical to those discussed in Penry II.6 [277]*277Because we discern no meaningful distinction between the charges given in Penry II and those given in the instant case, we find that Bigby has demonstrated that the contested jury instructions stripped the jury of a vehicle for expressing its “reasoned moral response”7 to the appropriateness of the death penalty. As in Penry 11, the verdict form in Bigby listed the three special issues but with no mention of mitigating circumstances. In short, the same constitutional infirmities criticized by the Supreme Court in Penry II are present in Bigby. Accordingly, since the decision of the Texas Court of Criminal Appeals is contrary to clearly established federal law, we reverse the district court’s denial of Bigby’s application for COA with regard to his jury instruction claim, vacate his sentence, and remand this case to the district court for entry of an order granting Bigby habeas relief on his Penry claim and setting aside his sentence.
B. Denial of the Right to Impeach Witnesses
Bigby contends that the trial court improperly denied him the right to impeach Grace Kehler, the chief witness against him, by showing that her pending civil suit provided a motive to testify falsely and by pointing out that Kehler had made contradictory allegations in the civil suit. A review of the record, however, reveals a different account of the trial proceedings. In particular, Judge Leonard did allow Bigby to question Kehler about any potential pecuniary interests arising from her unresolved wrongful death suit against Bigby’s physician and treating hospitals for failing to attend adequately his mental illness. The judge merely informed Big-by’s counsel that he would not allow the civil petitions into evidence unless Kehler denied the suit.
Bigby correctly notes that the Sixth Amendment guarantee of a criminal defendant’s right to confront witnesses against him includes the right to cross-examination. See Davis v. Alaska, 415 U.S. 308, 315, 94 S.Ct. 1105, 1110, 39 L.Ed.2d 347 (1974). But this right is subject to the wide latitude of trial judges to impose reasonable limits. See id. (stating that the right to cross-examination is “[sjubject always to the broad discretion of a trial judge to preclude repetitive and unduly harassing interrogation”); Delaware v. Van Arsdall, 475 U.S. 673, 679, 106 S.Ct. 1431, 1435, 89 L.Ed.2d 674 (1986). As such, the Confrontation Clause does not guarantee defendants cross-examination to whatever extent they desire. Van Arsdall, 475 U.S. at 678, 106 S.Ct. 1431. Bigby fails to demonstrate that his efforts to impeach Kehler were unconstitutionally circumscribed or that the state’s rejection of his impeachment complaints constitute an unreasonable application of clearly established federal law. Accordingly, no reason exists to issue a COA on this issue.
C. Shackled and Handcuffed in the Jury’s Presence
Bigby next contends that the trial court erred by shackling him during the trial and allowing the jury to see him handcuffed. “While a defendant is entitled to the physical indicia of innocence, a court is justified in ordering him handcuffed and shackled during trial [when] there is dan,ger of escape or injury to the jury, counsel, or other trial participants.” Wilkerson v. Whitley, 16 F.3d 64, 67 (5th Cir.1994); see also Holbrook v. Flynn, 475 U.S. 560, 568-69, 106 S.Ct. 1340, 1346, 89 L.Ed.2d 525 [278]*278(1986)(stating that shackling is permissible only when “justified by an essential state interest specific to each trial”); Illinois v. Allen, 397 U.S. 337, 343-44, 90 S.Ct. 1057, 1061, 25 L.Ed.2d 353 (1970)(opining that trial judges “must be given sufficient discretion” to ensure the “dignity, order, and decorum ... of all court proceedings” and concluding that binding and gagging an obstreperous defendant is constitutionally acceptable in some situations). After Big-by assaulted Judge Leonard, it was incontrovertible that he posed a real danger to all assembled in the trial court. Judge Leonard, therefore, was not beyond the bounds of his ample discretion to decide whether a defendant should be restrained when he ordered Bigby shackled and handcuffed. See Lockhart v. Johnson, 104 F.3d 54, 57 (5th Cir.1997)(“The decision to restrain an obstreperous defendant with visible restraints lies within the sound discretion of the trial judge.”)(citing Allen, 397 U.S. at 343-44, 90 S.Ct. 1057). Accordingly, a COA should not issue on this point.
D. Juror Challenges
Bigby next attempts to secure a COA by arguing that he was denied due process when the trial court altered the sequence established in Article 35.13 of the Texas Code of Criminal Procedure for challenging jurors in a capital case. “Article 35.13 states ... that the veniremen shall ‘be passed for acceptance or challenge first to the state and then to the defendant.’ ” Bigby, 892 S.W.2d at 879. Upon both parties’ completion of voir dire, the state must choose to accept the venire member or challenge him either for cause or peremptorily: only then should the defendant or his counsel exercise its peremptory or causal challenge. Id. at 880.
In Bigby’s case, the trial court ruled that the voir dire challenges of venire member 12 would proceed as follows: “State’s challenge for cause, appellant’s challenge for cause, State’s peremptory challenge, and appellant’s peremptory challenge.” Id. at 879. Arguing that this ruling violated the selection procedure set forth in Article 35.13, Bigby’s counsel objected. Id. Although the Texas Court of Criminal Appeals concluded that the district court erred in overruling this objection to the order of voir dire, it ultimately held the error to be harmless. Id. at 881-82.
In addressing Bigby’s claims for a grant of COA based on the irregularity in the sequence of challenges during voir dire, we note that violations of state law are not generally cognizable on habeas review unless the error renders the trial as a whole fundamentally unfair. See Fuller v. Johnson, 158 F.3d 903, 908 (5th Cir. 1998) (citing Engle v. Isaac, 456 U.S. 107, 135, 102 S.Ct. 1558, 1575, 71 L.Ed.2d 783 (1982)). Bigby fails to demonstrate that the tactical disadvantage, which he allegedly suffered as a result of the trial court’s deviation, resulted in a fundamentally unfair trial. Therefore, his claim is insufficient to support the issuance of a COA.
E. Ineffective Assistance of Counsel
After evidence of Bigby’s assault on Judge Leonard was admitted, defense counsel sought to withdraw from the case, arguing that they should be allowed to appear as witnesses regarding the incident and its relation to Bigby’s mental instability. Judge Leonard denied the request based on the unnecessary delay it would create, but suggested that only one of Big-by’s defense attorneys testify. Although such a course of action may have constituted a conflict of interest, neither of Bigby’s attorneys decided to take the stand. Big-by nonetheless asserts that those decisions [279]*279somehow denied him effective assistance of counsel.
Strickland v. Washington, 466 U.S. 668, 104 S.Ct. 2052, 80 L.Ed.2d 674 (1984), guides our review of Bigby’s ineffective assistance of counsel claim. Big-by’s burden is twofold. First, he must demonstrate that his counsel’s performance was deficient. See Strickland, 466 U.S. at 687,104 S.Ct. 2052. “This requires showing that counsel made errors so serious that counsel was not functioning as the ‘counsel’ guaranteed the defendant by the Sixth Amendment.” Id. Second, Bigby must demonstrate that the deficient performance prejudiced him. See id. “This requires showing that counsel’s errors were so serious as to deprive the defendant of a fair trial, a trial whose result is reliable.” Id. Bigby asserts no clear grounds for deficient performance and cannot show prejudice from a conflict of interest because his attorneys did not testify. Accordingly, a COA should not issue on this point.
F. Material Exculpatory Evidence Withheld
Finally, Bigby contends that the prosecution abridged his due process right by failing to provide medical records from the county jail that detailed the numerous psychotropic medications he was taking while incarcerated and awaiting trial. Due process is violated when the prosecution withholds material evidence favorable to the defense. Brady v. Maryland, 373 U.S. 83, 87, 83 S.Ct. 1194, 1196-97, 10 L.Ed.2d 215 (1963). The state, however, bears no responsibility to direct the defense toward potentially exculpatory evidence that either is in the possession of the defense or can be discovered through the exercise of reasonable diligence. Rector v. Johnson, 120 F.3d 551, 558-59 (5th Cir.1997). Because the records to which Bigby refers were available through the exercise of such reasonable diligence, a COA should not issue on this claim.
CONCLUSION
For the foregoing reasons, we AFFIRM Bigby’s conviction. We REVERSE the district court’s denial of Bigby’s application for COA with regard to his nullification instruction claim, GRANT the COA, VACATE Bigby’s sentence, and REMAND this case to the district court of entry of an order granting Bigby’s habeas relief on his Penry claim and setting aside his sentence.
AFFIRM in part, REVERSE in part, VACATE AND REMAND.