George DelVecchio1 was convicted of slashing the throat of six-year-old Tony Can-zoneri and of raping the child’s mother, Karen, and sentenced to die. DelVecchio was captured on the roof of the Canzoneris’ two-flat apartment when a Chicago police officer called to the scene of the rape heard snow crunching outside an attic window. DelVec-chio’s first words at being spotted were, “I didn’t kill nobody.” Later that morning— two days before Christmas 1977 — police found Tony’s body stuffed in a crawl space under the stairs; his trachea, carotid artery, jugular vein and vagus nerve were severed and his third and fourth cervical vertebrae were fractured. The motive of the slaying, apparently, was to allow the attacker to rape Karen Canzoneri without being interrupted. DelVecchio was convicted of murder, rape, deviate sexual assault and burglary.2
But he did not receive a fair trial. The judge had an extreme conflict of interest — as a prosecutor in an earlier case involving DelVecchio, he made critical decisions that resulted in the defendant being free, rather than in prison, at the time of Tony Canzoneri’s murder, and then as judge ruled *511on the admissibility of evidence about the first case — and he did not bother to tell the defense about his conflict. This, by the way, is the most benign interpretation of the judge’s silence. As a result, we direct Illinois under the habeas statute, 28 U.S.C. § 2254, to grant DelVecchio a new trial or release him.
I.
Karen Canzoneri could identify DelVecchio as her attacker because she knew him — in fact had invited him and his wife, Rose, to her house earlier in the evening of her son’s murder. After Karen, Tony and a friend of Karen’s, Santo Falcone, drove to Lombard, Illinois, to buy a stereo receiver, they stopped at a tavern where by happenstance they met the DelVecchios. The four adults, who knew each other, and Tony then left the bar and went to Karen Canzoneri’s house where the DelVecchios and Falcone smoked marijuana that George DelVecchio brought with him in a briefcase. In the meantime, Falcone put Tony to bed downstairs. Karen Canzoneri asked her visitors to leave after an hour and they did. But George DelVecchio returned at dawn, according to Mrs. Canzon-eri, this time without an invitation. He told her he wanted to talk. She felt threatened and pulled out a pistol; it would not fire and DelVecchio knocked the weapon from her hand. When she tried to leave him, DelVec-chio raped her. The phone rang twice and DelVecchio left Karen Canzoneri alone and went downstairs. She looked for a phone but found that its cord had been cut, so she ran from her house across the street to her mother’s and called the police. When Del-Vecchio was arrested crawling on the roof of the Canzoneris’ home, he had in his pocket a credit card Karen Canzoneri had left on the kitchen table. The police later discovered Tony’s body; the boy had been killed by a powerful blow to the neck with a knife.
DelVecchio was convicted after a jury trial and, in addition to the death sentence for Tony Canzoneri’s murder, received a fifteen-year term for rape, six years for deviate sexual assault and seven years for burglary. He has been sitting on death row in Illinois now for fourteen years. The defendant exhausted his remedies in Illinois and applied to the district court for habeas relief.3 Judge Holderman held that the state must grant DelVecchio a hearing about the voluntariness of his confession for a 1965 crime that figured prominently in these proceedings but otherwise rejected the writ. DelVecchio appeals the district court’s denial of other relief and the state cross-appeals the need for a hearing about the 1965 confession. We reverse the district court’s decision to deny DelVecchio a writ based on the claim that his trial was unfair because the judge was biased against him. We also affirm the district court’s holding that if Illinois wants to retry DelVecchio and introduce the confession as evidence, it must provide him with a hearing about its voluntariness.
This is not the first time DelVecchio has been convicted of murder. In 1965, when he was sixteen years old, DelVecchio and two friends, high on “goof balls” according to newspaper reports at the time, shot a sixty-six-year-old man named Fred Christiansen nine or ten times as he was walking down his street, Waveland Avenue in Chicago, to pick up a pack of cigarettes. DelVecchio and his comrades netted all of $11 from Christian-sen’s wallet. DelVecchio confessed. The case generated an extraordinary amount of press coverage — dozens of newspaper articles — because it was one of the first incidents in Chicago in which teenagers went on what might be called a senseless drug-induced rampage to capture money for drugs. It was thus a very high-profile case when it landed in the Cook County state’s attorney’s office, perhaps the second-most publicized case in the four-year tenure of Louis Garippo, chief of the state’s attorney’s criminal division. Chief criminal prosecutor Garippo later became a Cook County judge and in that capac*512ity, fourteen years after the Christiansen slaying, he presided over the capital trial of George DelVecchio for the murder of Tony Canzoneri.
Under Illinois law in 1965, any male who had yet to reach his seventeenth birthday but who was convicted and sentenced as an adult was sent to the Illinois Youth Commission (“IYC”) with no minimum mandatory term. Ill.Rev.Stat. ch. 23 §§ 2523-2525 (1963).4 The IYC then had total discretion: it could release the boy at any time before he turned twenty-one years old, it could release him when he turned twenty-one, or it could send him to an adult penitentiary at age twenty-one at which point the offender would receive a new sentence. Id. By contrast, any male sentenced after he turned seventeen received a normal adult term of years and served his time in a penitentiary. DelVeeehio’s case landed in the state’s attorney’s office in early February 1965; DelVecchio was set to turn seventeen on March 1, 1965 (DelVecchio was born February 29,1948, a leap year). Prosecutors, then, had they delayed sentencing for a few weeks, could have guaranteed that DelVecchio would serve time (and almost certainly more of it) in an adult institution. Here is the choice prosecutors faced: if Del-Vecchio were sentenced on February 28, 1965, he would go to a youth home and be eligible to be freed the next day; if he were sentenced on March 1, 1965, he would go to an adult penitentiary and receive a minimum mandatory sentence of fourteen years and possibly a sentence as high as fifty years. Ill.Rev.Stat.1963, ch. 38, sec. 9-1.
DelVecchio’s lawyer thought the state was intentionally delaying the indictment. He thus went to see Louis Garippo and proposed a deal: DelVecchio would plead guilty if Gar-ippo would allow the boy to be sentenced before his seventeenth birthday. Garippo agreed. The future judge expedited DelVec-chio’s indictment and he was sent to the IYC rather than to a state penitentiary. Considering that DelVecchio had already admitted in writing to shooting Christiansen — thus a conviction seemed assured even without a guilty plea — Garippo gave the young man an extraordinary break by speeding up the indictment. He also left himself and the state’s attorney’s office open to criticism for being soft on the criminals who had perpetrated such a shocking murder.
Garippo made other key decisions in the Christiansen case. He assigned his former trial partner, James Flynn, to represent Illinois in court against DelVecchio. He decided that DelVecchio would be charged as an adult rather than as a juvenile, which put the case before the circuit court’s criminal division rather than its juvenile division, where cases of offenders under age seventeen were routinely handled. Garippo received a memo about the Christiansen case and discussed the matter repeatedly with Flynn.5 And Garippo — though apparently he did not enter an official appearance on behalf of the state — attended the court proceedings at which DelVecchio entered a guilty plea and accepted his sentence.
When DelVecchio turned twenty-one in 1969, the IYC staff unanimously recommended parole but its top officials trans*513ferred him to an adult penitentiary for further incarceration. In 1971 he was brought before the circuit court to receive an adult sentence. With the brutal Christiansen murder having receded from public consciousness, and with such a sterling behavioral record at IYC that even the prosecutor admitted DelVecehio had done everything possible to rehabilitate himself, the judge imposed the lowest adult prison term available, fourteen years, which allowed the inmate to be paroled just two years later, in April 1973. In all, DelVecehio was incarcerated for eight years. It is likely that if Garippo had made a different decision — to delay indictment and sentencing a few weeks — DelVecehio would not have been released in 1973 and probably would have been in prison on December 22, 1977, the night of Tony Canzoneri’s death. This is more than mere speculation by defense lawyers desperate for habeas relief; prosecutors made the same argument to the jury in the sentencing phase of the trial— that had DelVecehio not received such gentle treatment by officials in the Christiansen murder, Tony Canzoneri would still be alive.
Whether or not Judge Garippo felt responsible for DelVecchio’s being free in late 1977, his statements suggest that as an elected judge he feels his personal reputation is at stake when he is lenient on a defendant. Garippo said in his deposition for this ease that judges “get their biggest criticism” if someone they have given a break to is “caught doing something.” Garippo tells any defendant he is sentencing to probation or releasing on recognizance that he is “wearing Garippo’s sweat shirt and if he fowled [sic] up while he was either out on personal bond or on probation, he would get that sweat shirt dirty and it had my name on it; and then I would feel very offended if someone had Garippo’s sweat shirt and dirtied that sweat shirt” (Garippo dep. of August 16, 1991, at 32).
The Christiansen killing did not merely lurk in the background of DelVeechio’s trial for the murder of Tony Canzoneri; it became the locus of a series of hotly contested evi-dentiary rulings by Judge Garippo. Before trial DelVecchio’s counsel, who intended to mount an insanity defense, made motions in limine to exclude use of the 1965 Christian-sen conviction and confession for three reasons: they were irrelevant to the 1977 murder; the 1965 confession had been involuntary and taken in violation of Miranda v. Arizona, 384 U.S. 436, 86 S.Ct. 1602, 16 L.Ed.2d 694 (1966); and the state’s attorney’s office improperly bypassed the circuit court juvenile division to indict DelVecehio as an adult. Judge Garippo delayed any decision on these issues until he heard the evidence, but he did not tell the defense of his role in the Christiansen case. In particular, he did not tell the defense that he was personally responsible for the decision to bypass the juvenile division that was now being challenged as improper. Well into the trial, Gar-ippo decided that he would permit prosecutors to use the Christiansen confession and conviction against DelVecehio unless the defendant withdrew his claim of insanity. Having delayed his ruling until much of the evidence had been presented, Judge Garippo forced DelVecehio’s lawyers to choose between letting the jury hear the damning evidence from 1965 or abandoning the insanity defense. They chose to drop the insanity defense. Judge Garippo told jurors that “something” had happened to shorten the trial, and he permitted prosecutors to argue in closing that the defendant “threw in the towel” on the insanity defense because “it was not working.” Judge Garippo then allowed the state to use the 1965 murder in the sentencing phase of the trial. Prosecutors argued to the jury that “experts” had fouled up once by giving DelVecehio a break as a teen-age killer, and that he should not receive a second chance in the form of a prison sentence rather than capital punishment lest experts err again:
Well, you can see that if George DelVec-chio from 1965 had served even the minimum from that sentence, fourteen years, Tony Canzoneri would be alive today and looking forward to Thanksgiving tomorrow. The so-called experts have said, let George DelVecehio out after serving eight years in custody, various juvenile facilities and then the Illinois State Penitentiary. They decided George DelVecehio had been rehabilitated. Those decisions from those *514so-called experts cost Tony Canzoneri his life.
DelVecchio I, 105 Ill.2d 414, 435-436, 86 Ill. Dec. 461, 475 N.E.2d 840. Prosecutors obviously did not realize as they made this argument that Judge Garippo was one of the supposed experts who had given DelVecchio a break in the 1965 case.
According to DelVecchio, he did not learn that Judge Garippo had any significant role in prosecuting him in the Christiansen murder until 1986, seven years after the trial in the Canzoneri case. By that point his death sentence had been affirmed on direct appeal. See id. The state resisted attempts to discover more information, but Garippo submitted an affidavit that said his personal involvement was “limited to two tasks”: assigning the case to his former law partner Flynn and agreeing to expedite the filing of charges so that DelVecchio could plead guilty as a juvenile. A state court judge denied DelVecchio’s request for more discovery and the state Supreme Court affirmed, DelVecchio II, 129 Ill.2d 265, 278, 135 Ill.Dec. 816, 544 N.E.2d 312, stating that Garippo’s role was minor. Not until Judge Holderman in the district court ordered that Judge Garippo be deposed did his full involvement in the 1965 case became known to the defense.
II.
We are authorized to grant a writ of habe-as corpus if a person is being held under a state court judgment in violation of the Constitution of the United States. 28 U.S.C. § 2254; Williams v. Chrans, 945 F.2d 926, 931 (7th Cir.1991), certiorari denied, — U.S. —, 112 S.Ct. 3002, 120 L.Ed.2d 877 (1992). We review the district court’s findings of fact under a clearly erroneous standard, Anderson v. City of Bessemer City, N.C., 470 U.S. 564, 573, 105 S.Ct. 1504, 1511, 84 L.Ed.2d 518 (1985), although we must reverse if there are genuine issues of material fact construed in the light most favorable to the defendant. Richardson v. Penfold, 839 F.2d 392, 394 (7th Cir.1988). Of course we subject the district court’s findings of law and mixed findings of law and fact to de novo review. Brewer v. Aiken, 935 F.2d 850, 855 (7th Cir.1991).
One of the most basic values of our constitutional system is that the judge who hears a case must be personally disinterested in the outcome. The central formulation of the principle was enunciated in Tumey v. Ohio: “Every procedure which would offer a possible temptation to the average man as a judge to forget the burden of proof required to convict the defendant, or which might lead him not to hold the balance nice, clear and true between the state and the accused denies the latter due process of law.” 273 U.S. 510, 532, 47 S.Ct. 437, 444, 71 L.Ed. 749 (1927). While not every issue of judicial qualification involves constitutional validity, id. at 523, 47 S.Ct. at 441, and mere general allegations in a civil case of bias and prejudice are insufficient to offend due process, Aetna Life Ins. Co. v. Lavoie, 475 U.S. 813, 821, 106 S.Ct. 1580, 1585, 89 L.Ed.2d 823 (1986), “it certainly violates the 14th Amendment and deprives a defendant in a criminal case of due process of law to subject his liberty or property to the judgment of a court, the judge of which has a direct, personal, substantial pecuniary interest in reaching a conclusion against him in his case.” Tumey, 273 U.S. at 523, 47 S.Ct. at 441. The Court in Turney omitted the obvious corollary, but we stress it here because this is a death penalty case: it violates a defendant’s due process rights to subject his life, as well as his liberty and property, to the judgment of a court in which the judge is not neutral or fair. Suggestions of judicial impropriety always receive our highest attention because they undermine respect for law. But particularly in a capital case where the consequences of error are so grave, a court must be especially vigilant that the defendant received a fair trial. “Because the death penalty is qualitatively and morally different from any other penalty, ‘[i]t is of vital importance to the defendant and to the community that any decision to impose the death sentence be, and appear to be, the consequence of scrupulously fair procedures.’ ” Sawyer v. Whitley, — U.S.—,—, 112 S.Ct. 2514, 2530, 120 L.Ed.2d 269 (1992) (Stevens, J., concurring) (quoting Smith v. Murray, 477 U.S. 527, 545-546, 106 S.Ct. 2661, 2672, 91 L.Ed.2d 434 (1986) (Stevens, J., dissenting)).
*515We have not considered whether a criminal defendant must, to prove a due process violation, show that the judge in his case was actually biased against him, or whether it is sufficient that the judge merely appeared to be prejudiced against him. The district court speculated, based on our decisions in Margoles v. Johns, 660 F.2d 291 (1981), certiorari denied, 455 U.S. 909, 102 S.Ct. 1256, 71 L.Ed.2d 447 (1982), and Walberg v. Israel, 766 F.2d 1071, certiorari denied, 474 U.S. 1013, 106 S.Ct. 546, 88 L.Ed.2d 475 (1985), and two cases from the Sixth Circuit, Corbett v. Bordenkircher, 615 F.2d 722, certiorari denied, 449 U.S. 853, 101 S.Ct. 146, 66 L.Ed.2d 66 (1980), and Jenkins v. Bordenkircher, 611 F.2d 162 (1979), certiorari denied, 446 U.S. 943, 100 S.Ct. 2169, 64 L.Ed.2d 798 (1980), that we would require actual bias. But Margóles was a civil case — moreover, a civil case where the allegations of judicial conflict were utterly unpersuasive: a judge had been Wisconsin’s attorney general years before when the plaintiff was involved in a dispute with the state’s medical examining board on a matter unrelated to the subsequent litigation. And in Walberg we did not have to decide whether actual bias is required in the criminal context because in that case the judge’s blatant hostility toward the defendant’s lawyer deprived the accused of effective assistance of counsel. 766 F.2d at 1077. As for the decisions from the Sixth Circuit, which of course are not binding here, these merely declined to establish a per se rule that any former involvement by a prosecutor-turned-judge in an unrelated case against the defendant violates the Constitution. Corbett, 615 F.2d at 724; Jenkins, 611 F.2d at 166.
Not only are these cases beside the point, but the Supreme Court has repeatedly answered this very question by noting that the appearance of justice is as important as the reality of justice, or at least important enough that its absence violates due process. In Taylor v. Hayes, 418 U.S. 488, 94 S.Ct. 2697, 41 L.Ed.2d 897 (1974), the Court held in a criminal case that a defendant should not be tried by the same judge who appeared prejudiced against him in an initial trial. After quoting Tumey v. Ohio, the Court said, “In making this ultimate judgment, the inquiry must be not only whether there was actual bias on respondent’s [judge’s] part, but also whether there was ‘such likelihood of bias or an appearance of bias that the judge was unable to hold the balance between vindicating the interests of the court and the interests of the accused.’ ” Id. at 501, 94 S.Ct. at 2704 (quoting Ungar v. Sarafite, 376 U.S. 575, 588, 84 S.Ct. 841, 849, 11 L.Ed.2d 921. (1964)). And in In re Murchison, the Court said:
Fairness of course requires an absence of actual bias in the trial of cases. But our system of law has always endeavored to prevent even the probability of unfairness. * * * Such a stringent rule [as set out in Tumey ] may sometimes bar trial by judges who have no actual bias and who would do their very best to weigh the scales of justice equally between contending parties. But to perform its high function in the best way “justice must satisfy the appearance of justice.”
349 U.S. 133, 136, 75 S.Ct. 623, 625, 99 L.Ed. 942 (1955) (quoting Offutt v. United States, 348 U.S. 11, 14, 75 S.Ct. 11, 13, 99 L.Ed. 11 (1954)). There is also a practical reason to demand that judges recuse themselves whenever there is an appearance of impropriety: proving actual bias is frequently impossible. Of course judges have personal feelings about the cases they try; one cannot expect and should not desire a lack of humanity. But since even a judge with the strongest distaste for a defendant is hardly likely to blurt out, “I am out to get you,” the only practical way to demonstrate partiality or conflict is by circumstance and inference. To require a criminal defendant to prove actual bias would ensure that no one could ever succeed in showing that their Fourteenth Amendment rights have been transgressed by a partial judge.6
*516The potential conflict need not be financial. Although Tumey referred to pecuniary interests by the judge, 273 U.S. at 523, 47 S.Ct. at 441, the Supreme Court in In re Murchison held that a judge cannot both take a case before a grand jury and then sit in judgment of it because “[hjaving been a part of that process a judge cannot be, in the very nature of things, wholly disinterested in the conviction or acquittal of those accused.” 349 U.S. at 137, 75 S.Ct. at 625-626. No financial interest was present in Murchison or in Bloom v. Illinois, 391 U.S. 194, 202, 88 S.Ct. 1477, 1482, 20 L.Ed.2d 522 (1968), where the bias' emanated from personal insults hurled by the defendant that struck “at the most vulnerable and human qualities of a judge’s temperament.” See also Ward v. Village of Monroeville, 409 U.S. 57, 93 S.Ct. 80, 34 L.Ed.2d 267 (1972) (mayor could not sit as judge of municipal violations). In deciding these cases, the Court merely recognized that human motivations often turn on matters in addition to money. We would not, for example, allow a judge to try a defendant accused of murdering the judge’s husband. Nor would a judge be permitted to try a defendant when the judge had won election by pointing to the individual accused as an example of someone who should be executed — even if, by some miracle of science, we were able to enter the judge’s head to discover that she had not prejudged the case.
The dissent, however, would enunciate a new standard under which the appearance of impropriety would be acceptable so long as there was not ‘“some [actual] incentive to find one way or the other’ or ‘a real possibility of bias’ * * * ” (dissent at 521). We do not disagree that the incentive to be biased or the real possibility of bias may be important considerations in determining whether there is an appearance of prejudice. But there is little in Supreme Court precedent to suggest that the appearance of prejudice is limited to these circumstances. Having an incentive to be biased and the possibility of using that bias to injure a defendant are really just variants of the idea that judges must not appear partial. To the extent that these notions are evident in the case law, they merely reflect the concern that the appearance of partiality, to constitute a due process violation, must not be trivial. And Garippo’s conflict was in no sense trivial. In fact, Judge Garippo’s actions in the Canzon-eri case were so egregious that even if proof of actual bias were required, we would still hold that the judge’s conflict of interest violated the defendant’s due process rights.
By acting as George DelVecchio’s trial judge after serving as criminal division chief during the Christiansen murder proceedings, Judge Garippo violated the basic principle of judicial neutrality in two respects. First and most egregious, he was forced to sit in judgment of his own decisions as a prosecutor. It is simply inexcusable for the judge to have considered a motion to strike the 1965 conviction on the grounds that DelVecchio should have been tried as a juvenile when Garippo himself decided that he would be prosecuted as an adult. Moreover, the validity of the 1965 confession and conviction was one of the pivotal issues in the Canzoneri case, in part because Judge Garippo forced DelVecchio’s lawyers to abandon the insanity defense under threat that the Christiansen murder would otherwise come into evidence.
The second way Judge Garippo violated judicial neutrality was by hearing a case against a defendant about whom it would have been natural for the judge to hold a grudge. Arguably, Judge Garippo bore some personal responsibility for the fact that DelVecchio was not incarcerated at the time of Tony Canzoneri’s death — as noted, prosecutors made just such an argument to the jury in closing when they said that “experts” in the Christiansen case badly misjudged the accused. Perhaps the judge did not feel biased against DelVecchio and did not allow personal sentiment to infect his judgment at the trial. But we have at least circumstantial evidence that Garippo was predisposed against DelVecchio based on his deposition testimony that he feels personally betrayed when a defendant on whom he has been lenient commits another crime. More specif*517ically, the record contains an affidavit from a court employee who said that the files from the Christiansen murder ease had been signed out to Judge Garippo’s courtroom clerk before the trial in the Canzoneri slaying started and thus before the judge had any reason to examine the old files. The judge also went out of his way to opine that DelVecchio was more deserving of the death penalty than John Wayne Gacy, who was convicted in Garippo’s court of committing thirty-three murders and who also received a death sentence. Even disregarding this substantial evidence that Garippo took an unusual personal interest in DelVecchio’s case, the judge was still obliged to recuse himself if from the vantage of the defendant, a rational person accused of a crime could not be convinced that he received a fair trial under these circumstances. Walberg, 766 F.2d at 1077. According to the dissent, Judge Garip-po was not biased against DelVecchio because he had no financial interest in the case, had not been insulted by the defendant or his attorneys, and did not serve in the dual roles of judge and prosecutor. With all respect, this is simply wrong. Garippo prosecuted DelVecchio and then had occasion to revisit his decisions as a judge. That Garippo’s dual roles were enacted in separate proceedings hardly negates the fact that Garippo was passing judgment on his own decisions as a prosecutor. And though DelVecchio may not have insulted the judge in the courtroom as in Bloom, 391 U.S. at 202, 88 S.Ct. at 1482, Garippo revealed in his deposition that he feels personally insulted and betrayed when a defendant he has favored with lenient-treatment goes awry and “dirtie[s] * * * Garippo’s sweat shirt” (Garippo deposition of Aug. 16, 1991, at 32).
We emphasize that this is not simply a matter of a judge having been a non-participating member of a prosecutor’s office trying an unrelated case against the defendant. Nor is this the case of an office supervisor handling hundreds of routine matters and making only ministerial judgments. This judge was the central decision maker in the 1965 prosecution against DelVecchio. Had he been the attorney of record for Illinois, the conflict might be more obvious but it would not be any more substantial. United States v. Ziegenhagen, 890 F.2d 937, 941 (7th Cir.1989) (former prosecutor had conflict of interest even though he was not attorney of record). In fact, had the defendant sought out Louis Garippo to act as his trial counsel in the Canzoneri slaying, he would have been obliged to decline because of his earlier dealings with DelVecchio as a prosecutor. Id. at 940-941. We can expect no less from judges.7
Finally, Judge Garippo exacerbated the conflict by not telling counsel for the defense or prosecution about it at trial or after. The most charitable assessment of this omission is that perhaps the judge did not recall or realize the significance of the conflict. Yet between the judge’s silence and the state’s lengthy efforts to resist discovery, the defense was kept in the dark for nearly fifteen years. This silence deprived DelVecchio of the opportunity to seek Judge Garippo’s re-cusal at trial, caused undue delay, wasted judicial resources, prejudiced DelVecchio by forcing him to raise the matter on habeas rather than on direct appeal, and now it requires us to set aside the jury’s verdict in its entirety.
III.
We must address one last issue. DelVecchio both confessed and pled guilty to the *5181965 murder of Fred Christiansen. He does not now claim that his guilty plea was involuntary, but he challenges the validity of the confession. The question is whether, having pled guilty to killing Christiansen, DelVec-chio waived whatever rights he might have had to challenge the voluntariness of the confession. Judge Garippo refused to grant DelVecchio a hearing before allowing the state to use the confession as evidence in aggravation in DelVeechio’s sentencing for the Canzoneri murder. The Illinois Supreme Court summarily affirmed. DelVecchio I, 105 Ill.2d at 432-433, 86 Ill.Dec. 461, 475 N.E.2d 840. The district court, however, agreed with DelVecchio that there must be a hearing to explore the voluntariness of the confession before it can be used to enhance his sentence for another murder. Obviously, our granting of the habeas writ extinguishes the death sentence and with it whatever error Judge Garippo might have made in allowing the jury to hear evidence of the confession. But in the interests of judicial economy — should the state retry DelVecchio, prosecutors are certain to try to introduce the Christiansen confession to enhance whatever sentence he may receive, even in a non-capital case — we note our agreement with the district court.
Uncounseled convictions cannot be used against a person to support a guilty verdict or to enhance punishment for another offense. Burgett v. Texas, 389 U.S. 109, 115, 88 S.Ct. 258, 262, 19 L.Ed.2d 319 (1967). Illinois posits two arguments why DelVecchio has lost the right to challenge the 1965 confession, both of which hinge on the same misunderstanding. Under Ford v. Georgia, a state may erect a so-called procedural bar based on a “firmly established and regularly followed state practice” and thus keep defendants from raising certain constitutional issues on collateral appeal. 498 U.S. 411, 423-424, 111 S.Ct. 850, 857, 112 L.Ed.2d 935 (1991) (quoting James v. Kentucky, 466 U.S. 341, 348-351, 104 S.Ct. 1830, 1835-1837, 80 L.Ed.2d 346 (1984)). But the practice must be regularly followed; it cannot have been “manufactured for the occasion” of preventing this defendant the right to appeal. Prihoda v. McCaughtry, 910 F.2d 1379, 1384 (7th Cir.1990). Here an Illinois procedural rule prevents defendants who have pled guilty from challenging the constitutionality of their confessions in those cases. People v. Brown, 41 Ill.2d 503, 505, 244 N.E.2d 159 (1969). Illinois thus argues that DelVecchio lost his right to contest his 1965 confession when he swore in state court that he had murdered Fred Christiansen. The flaw in the state’s reasoning is that DelVecchio is not now attacking his 1965 confession for purposes of overturning the 1965 conviction; he is merely challenging use of the confession to enhance his sentence for the murder of Tony Canzoneri. Even the state admits the issue is novel: “[Tjhere are no Illinois cases in which a defendant has attacked a conviction in an earlier case in which he pleaded guilty, when that conviction was later used by the government in a subsequent case for purposes of aggravation at sentencing” (state’s brief at 9). If the issue has never come up before, as Illinois concedes, then there cannot be a well-established and regularly applied procedural bar to prevent Del-Vecchio’s claims.
Illinois also argues that DelVecchio may not relitigate the voluntariness of his confession under the rule in Tollett v. Henderson, 411 U.S. 258, 267, 93 S.Ct. 1602, 1608, 36 L.Ed.2d 235 (1973), that “a guilty plea represents a break in the chain of events which has preceded it in the criminal process.” But again, DelVecchio is not now attacking his 1965 confession for the purpose of claiming that his guilty plea in the Christiansen murder was in any way improperly obtained. In Haring v. Prosise, 462 U.S. 306, 103 S.Ct. 2368, 76 L.Ed.2d 595 (1983), a state similarly argued that a defendant who had pled guilty could not bring a § 1983 claim based on an allegedly illegal search and seizure. The Court held that a guilty plea did not cut off constitutional challenges to everything that came before, only constitutional challenges to the conviction itself. As the Court said,
Our decisions in Tollett and the cases that followed simply recognized that when a defendant is convicted pursuant to his guilty plea rather than a trial, the validity of that conviction cannot be affected by an *519alleged Fourth Amendment violation because the conviction does not rest in any way on evidence that may have been improperly seized. * * * Therefore, the conclusion that a Fourth Amendment claim ordinarily may not be raised in a habeas proceeding following a plea of guilty does not rest on any notion of waiver, but rests on the simple fact that the claim is irrelevant to the constitutional validity of the conviction.
Id. at 321, 103 S.Ct. at 2377. Although Del-Vecchio’s claim is not based on the Fourth Amendment, and he is not seeking monetary damages in a § 1983 action, the same reasoning applies. If anything, DelVecchio’s argument that his 1965 guilty plea did not extinguish his right to challenge his 1965 confession in a 1977 murder case is stronger than the defendant’s claim in Haring. Here the state is attempting to use the 1965 confession in a proceeding entirely unrelated to the case in which DelVecehio pled guilty, unlike Haring where the § 1983 action grew out of the same crime as the guilty plea. And DelVec-chio is challenging the voluntariness of his confession under the Fifth Amendment, a claim that raises even more weighty issues about the reliability of a conviction than an illegal search and seizure, the subject of the claim in Haring. See Mapp v. Ohio, 367 U.S. 643, 81 S.Ct. 1684, 6 L.Ed.2d 1081 (1961); Weeks v. United States, 232 U.S. 383, 34 S.Ct. 341, 58 L.Ed. 652 (1914). As in Haring, a defendant’s decision to plead guilty simply does not convey sufficient information to conclude that the confession was not coerced or that the evidence against him was not seized illegally. In this instance, for example, DelVecchio’s guilty plea was very likely motivated by a simple desire to take advantage of prosecutor Garippo’s willingness to allow him to be sentenced before he turned seventeen years old. The state points to a recent Supreme Court decision, Parke v. Raley, — U.S. —, 113 S.Ct. 517, 121 L.Ed.2d 391 (1992), holding that a presumption of regularity attaches to final judgments. But again, DelVecehio is not challenging the final judgment in the Christiansen murder.
Finally, we agree with Judge Holderman that this error was not harmless and that the state must prove that DelVec-chio’s 1965 confession was voluntary, rather than DelVecehio having to prove that the confession was involuntary. The 1965 evidence played a pivotal role in DelVecchio’s sentencing for the Canzoneri murder; if the confession on which much of the evidence was based was gained by coercion, the error can in no sense be considered harmless. And the state must bear the burden of proof because, with DelVecehio having pled guilty at trial, the state never had to prove by a preponderance of the evidence as it must in a criminal trial that the confession was voluntary. Martin v. Wainwright, 770 F.2d 918, 925 (11th Cir.1985), certiorari denied, 479 U.S. 909, 107 S.Ct. 307, 93 L.Ed.2d 281 (1986).
The district court’s holding concerning the 1965 confession is affirmed. Its holding regarding Judge Garippo’s failure to recuse himself is reversed and Illinois is directed to grant DelVecehio a new trial or release him.8
. Earlier decisions have spelled defendant’s name with a space: Del Vecchio. His briefs to this Court omit the space. We will honor the spelling preferred by the defendant.
. At the time of DelVecchio’s conviction, the statutes he was charged with violating were numbered as follows: murder (IIl.Rev.Stat.1975, ch. 38, sec. 9 — 1(a)(2)); rape (Ill.Rev.Stat.1975, ch. 38, sec. 11-1); deviate sexual assault (Ill.Rev. Stat.1975, ch. 38, sec. 11-3); and burglary (Ill. Rev.Stat.1975, ch. 38, sec. 19-1). The jury found that there were aggravating circumstances concerning the murder and no mitigating circumstances under IIl.Rev.Stat.1975, ch. 38, sec. 9-1(b), and recommended a death sentence. The trial judge accepted the jury's recommendation.
. Ill.Rev.Stat.1963, ch. 23 § 2525 provided in part:
1. The control by the Commission of a person committed as a delinquent shall cease when such person reaches the age of 21 years;
2. The control by the Commission of a person committed in a criminal proceeding shall cease at the expiration of the maximum term provided by law for the offense for which he was committed and he shall thereupon be discharged, but if such maximum term does not expire until after his twenty-first birthday the control and custody of the Commission over such person shall cease on his twenty-first birthday and he shall immediately become subject to the control and custody of the Department of Public Safety or if on parole of the Parole and Pardon Board * * 5. The Commission shall notify such person and the Department of Public Safety or the Parole and Pardon Board at least 60 days before the twenty-first birthday of such person, and shall hold such person subject to the order of such department or board. The Commission may enter into cooperative agreements with the Department of Public Safety and the Parole and Pardon Board to facilitate the transfer of such persons.
. After the state successfully resisted for several years the defense's attempts in state court to secure a copy of one such memorandum written by an assistant state's attorney, Illinois was ordered by the district court to produce it. The state then claimed the memo was lost.
. The difficulty is illustrated by the dissent's treatment of DelVecchio’s claims. Disputing the inference of actual bias that might be drawn from one of Judge Garippo’s statements to Del-Vecchio’s counsel, Judge Manion asks, "If Judge Garippo was trying to railroad DelVecchio, why would he tell DelVecchio's lawyer?” (dissent at 528). Under Judge Manion's approach, the de*516fendant could never win. If the judge is silent there is no proof of actual bias. And if the judge does say things that sound partial, there is still no evidence of bias because if the judge were really partial, he would have been smart enough to remain silent.
. The dissent analogizes Judge Garippo’s conduct to that of various Supreme Court justices who heard cases after writing extensively in the same field. These things are not comparable. We do not expect judges to come to the bench without views on public controversies that may come before them in one form or another. But there is a fundamental difference between having expressed views on an abstract matter of law and having prejudged an individual defendant in a criminal case. This is the difference between the general and the specific. Many judges, for exam-pie, are former prosecutors with set notions about the criminal law; these judges need not recuse themselves from every criminal case. However, we certainly expect them to recuse themselves where they have prosecuted a particular defendant. In Laird v. Tatum, 409 U.S. 824, 828, 93 S.Ct. 7, 10, 34 L.Ed.2d 50 (1972), Chief Justice Rehnquist expressed his approval of disqualification of a judge "if he actively participated in any case even though he did not sign a pleading or brief.”
. Other issues raised by the defendant need not be resolved here because the conflict of interest issue is dispositive. However, our failure to consider these questions does not imply that they are without merit.