(Slip Opinion)              OCTOBER TERM, 2015                                       1

                                       Syllabus

         NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
       being done in connection with this case, at the time the opinion is issued.
       The syllabus constitutes no part of the opinion of the Court but has been
       prepared by the Reporter of Decisions for the convenience of the reader.
       See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

                   WILLIAMS v. PENNSYLVANIA

   CERTIORARI TO THE SUPREME COURT OF PENNSYLVANIA

    No. 15–5040. Argued February 29, 2016—Decided June 9, 2016
Petitioner Williams was convicted of the 1984 murder of Amos Norwood
  and sentenced to death. During the trial, the then-district attorney
  of Philadelphia, Ronald Castille, approved the trial prosecutor’s re-
  quest to seek the death penalty against Williams. Over the next 26
  years, Williams’s conviction and sentence were upheld on direct ap-
  peal, state postconviction review, and federal habeas review. In
  2012, Williams filed a successive petition pursuant to Pennsylvania’s
  Post Conviction Relief Act (PCRA), arguing that the prosecutor had
  obtained false testimony from his codefendant and suppressed mate-
  rial, exculpatory evidence in violation of Brady v. Maryland, 373
  U. S. 83. Finding that the trial prosecutor had committed Brady vio-
  lations, the PCRA court stayed Williams’s execution and ordered a
  new sentencing hearing. The Commonwealth asked the Pennsylva-
  nia Supreme Court, whose chief justice was former District Attorney
  Castille, to vacate the stay. Williams filed a response, along with a
  motion asking Chief Justice Castille to recuse himself or, if he de-
  clined to do so, to refer the motion to the full court for decision.
  Without explanation, the chief justice denied Williams’s motion for
  recusal and the request for its referral. He then joined the State Su-
  preme Court opinion vacating the PCRA court’s grant of penalty-
  phase relief and reinstating Williams’s death sentence. Two weeks
  later, Chief Justice Castille retired from the bench.
Held:
     1. Chief Justice Castille’s denial of the recusal motion and his sub-
  sequent judicial participation violated the Due Process Clause of the
  Fourteenth Amendment. Pp. 5–12.
        (a) The Court’s due process precedents do not set forth a specific
  test governing recusal when a judge had prior involvement in a case
  as a prosecutor; but the principles on which these precedents rest dic-
2                     WILLIAMS v. PENNSYLVANIA

                                  Syllabus

    tate the rule that must control in the circumstances here: Under the
    Due Process Clause there is an impermissible risk of actual bias
    when a judge earlier had significant, personal involvement as a pros-
    ecutor in a critical decision regarding the defendant’s case. The
    Court applies an objective standard that requires recusal when the
    likelihood of bias on the part of the judge “is too high to be constitu-
    tionally tolerable.” Caperton v. A. T. Massey Coal Co., 556 U. S. 868,
    872. A constitutionally intolerable probability of bias exists when the
    same person serves as both accuser and adjudicator in a case. See In
    re Murchison, 349 U. S. 133, 136–137. No attorney is more integral
    to the accusatory process than a prosecutor who participates in a ma-
    jor adversary decision. As a result, a serious question arises as to
    whether a judge who has served as an advocate for the State in the
    very case the court is now asked to adjudicate would be influenced by
    an improper, if inadvertent, motive to validate and preserve the re-
    sult obtained through the adversary process. In these circumstances,
    neither the involvement of multiple actors in the case nor the passage
    of time relieves the former prosecutor of the duty to withdraw in or-
    der to ensure the neutrality of the judicial process in determining the
    consequences his or her own earlier, critical decision may have set in
    motion. Pp. 5–8.
          (b) Because Chief Justice Castille’s authorization to seek the
    death penalty against Williams amounts to significant, personal in-
    volvement in a critical trial decision, his failure to recuse from Wil-
    liams’s case presented an unconstitutional risk of bias. The decision
    to pursue the death penalty is a critical choice in the adversary pro-
    cess, and Chief Justice Castille had a significant role in this decision.
    Without his express authorization, the Commonwealth would not
    have been able to pursue a death sentence against Williams. Given
    the importance of this decision and the profound consequences it car-
    ries, a responsible prosecutor would deem it to be a most significant
    exercise of his or her official discretion. The fact that many jurisdic-
    tions, including Pennsylvania, have statutes and professional codes of
    conduct that already require recusal under the circumstances of this
    case suggests that today’s decision will not occasion a significant
    change in recusal practice. Pp. 9–12.
       2. An unconstitutional failure to recuse constitutes structural error
    that is “not amenable” to harmless-error review, regardless of wheth-
    er the judge’s vote was dispositive, Puckett v. United States, 556 U. S.
    129, 141. Because an appellate panel’s deliberations are generally
    confidential, it is neither possible nor productive to inquire whether
    the jurist in question might have influenced the views of his or her
    colleagues during the decisionmaking process. Indeed, one purpose of
    judicial confidentiality is to ensure that jurists can reexamine old
                     Cite as: 579 U. S. ____ (2016)                     3

                                Syllabus

  ideas and suggest new ones, while both seeking to persuade and be-
  ing open to persuasion by their colleagues. It does not matter wheth-
  er the disqualified judge’s vote was necessary to the disposition of the
  case. The fact that the interested judge’s vote was not dispositive
  may mean only that the judge was successful in persuading most
  members of the court to accept his or her position—an outcome that
  does not lessen the unfairness to the affected party. A multimember
  court must not have its guarantee of neutrality undermined, for the
  appearance of bias demeans the reputation and integrity not just of
  one jurist, but of the larger institution of which he or she is a part.
  Because Chief Justice Castille’s participation in Williams’s case was
  an error that affected the State Supreme Court’s whole adjudicatory
  framework below, Williams must be granted an opportunity to pre-
  sent his claims to a court unburdened by any “possible temptation . . .
  not to hold the balance nice, clear and true between the State and the
  accused,” Tumey v. Ohio, 273 U. S. 510, 532. Pp. 12–14.
__ Pa. __, 105 A. 3d 1234, vacated and remanded.

  KENNEDY, J., delivered the opinion of the Court, in which GINSBURG,
BREYER, SOTOMAYOR, and KAGAN, JJ., joined. ROBERTS, C. J., filed a
dissenting opinion, in which ALITO, J., joined. THOMAS, J., filed a dis-
senting opinion.
                        Cite as: 579 U. S. ____ (2016)                              1

                             Opinion of the Court

     NOTICE: This opinion is subject to formal revision before publication in the
     preliminary print of the United States Reports. Readers are requested to
     notify the Reporter of Decisions, Supreme Court of the United States, Wash-
     ington, D. C. 20543, of any typographical or other formal errors, in order
     that corrections may be made before the preliminary print goes to press.


SUPREME COURT OF THE UNITED STATES
                                   _________________

                                   No. 15–5040
                                   _________________


         TERRANCE WILLIAMS, PETITIONER v.

                 PENNSYLVANIA

    ON WRIT OF CERTIORARI TO THE SUPREME COURT OF 

           PENNSYLVANIA, EASTERN DISTRICT

                                 [June 9, 2016]

   JUSTICE KENNEDY delivered the opinion of the Court.
   In this case, the Supreme Court of Pennsylvania vacated
the decision of a postconviction court, which had granted
relief to a prisoner convicted of first-degree murder and
sentenced to death. One of the justices on the State Su-
preme Court had been the district attorney who gave his
official approval to seek the death penalty in the prisoner’s
case. The justice in question denied the prisoner’s motion
for recusal and participated in the decision to deny relief.
The question presented is whether the justice’s denial of
the recusal motion and his subsequent judicial participa-
tion violated the Due Process Clause of the Fourteenth
Amendment.
   This Court’s precedents set forth an objective standard
that requires recusal when the likelihood of bias on the
part of the judge “ ‘is too high to be constitutionally tolera-
ble.’ ” Caperton v. A. T. Massey Coal Co., 556 U. S. 868,
872 (2009) (quoting Withrow v. Larkin, 421 U. S. 35, 47
(1975)). Applying this standard, the Court concludes that
due process compelled the justice’s recusal.
2               WILLIAMS v. PENNSYLVANIA

                     Opinion of the Court

                             I
   Petitioner is Terrance Williams. In 1984, soon after
Williams turned 18, he murdered 56-year-old Amos Nor-
wood in Philadelphia. At trial, the Commonwealth pre-
sented evidence that Williams and a friend, Marc Draper,
had been standing on a street corner when Norwood drove
by. Williams and Draper requested a ride home from
Norwood, who agreed. Draper then gave Norwood false
directions that led him to drive toward a cemetery. Wil-
liams and Draper ordered Norwood out of the car and into
the cemetery. There, the two men tied Norwood in his
own clothes and beat him to death. Testifying for the
Commonwealth, Draper suggested that robbery was the
motive for the crime. Williams took the stand in his own
defense, stating that he was not involved in the crime and
did not know the victim.
   During the trial, the prosecutor requested permission
from her supervisors in the district attorney’s office to
seek the death penalty against Williams. To support the
request, she prepared a memorandum setting forth the
details of the crime, information supporting two statutory
aggravating factors, and facts in mitigation. After review-
ing the memorandum, the then-district attorney of Phila-
delphia, Ronald Castille, wrote this note at the bottom of
the document: “Approved to proceed on the death penalty.”
App. 426a.
   During the penalty phase of the trial, the prosecutor
argued that Williams deserved a death sentence because
he killed Norwood “ ‘for no other reason but that a kind
man offered him a ride home.’ ” Brief for Petitioner 7. The
jurors found two aggravating circumstances: that the
murder was committed during the course of a robbery and
that Williams had a significant history of violent felony
convictions. That criminal history included a previous
conviction for a murder he had committed at age 17. The
jury found no mitigating circumstances and sentenced
                 Cite as: 579 U. S. ____ (2016)           3

                     Opinion of the Court

Williams to death. Over a period of 26 years, Williams’s
conviction and sentence were upheld on direct appeal,
state postconviction review, and federal habeas review.
   In 2012, Williams filed a successive petition pursuant to
Pennsylvania’s Post Conviction Relief Act (PCRA), 42 Pa.
Cons. Stat. §9541 et seq. (2007). The petition was based on
new information from Draper, who until then had refused
to speak with Williams’s attorneys. Draper told Wil-
liams’s counsel that he had informed the Commonwealth
before trial that Williams had been in a sexual relation-
ship with Norwood and that the relationship was the real
motive for Norwood’s murder. According to Draper, the
Commonwealth had instructed him to give false testimony
that Williams killed Norwood to rob him. Draper also
admitted he had received an undisclosed benefit in ex-
change for his testimony: the trial prosecutor had prom-
ised to write a letter to the state parole board on his be-
half. At trial, the prosecutor had elicited testimony from
Draper indicating that his only agreement with the prose-
cution was to plead guilty in exchange for truthful testi-
mony. No mention was made of the additional promise to
write the parole board.
   The Philadelphia Court of Common Pleas, identified in
the proceedings below as the PCRA court, held an eviden-
tiary hearing on Williams’s claims. Williams alleged in
his petition that the prosecutor had procured false testi-
mony from Draper and suppressed evidence regarding
Norwood’s sexual relationship with Williams. At the
hearing, both Draper and the trial prosecutor testified
regarding these allegations. The PCRA court ordered the
district attorney’s office to produce the previously undis-
closed files of the prosecutor and police. These documents
included the trial prosecutor’s sentencing memorandum,
bearing then-District Attorney Castille’s authorization to
pursue the death penalty. Based on the Commonwealth’s
files and the evidentiary hearing, the PCRA court found
4               WILLIAMS v. PENNSYLVANIA

                     Opinion of the Court

that the trial prosecutor had suppressed material, excul-
patory evidence in violation of Brady v. Maryland, 373
U. S. 83 (1963), and engaged in “prosecutorial gamesman-
ship.” App. 168a. The court stayed Williams’s execution
and ordered a new sentencing hearing.
   Seeking to vacate the stay of execution, the Common-
wealth submitted an emergency application to the Penn-
sylvania Supreme Court. By this time, almost three dec-
ades had passed since Williams’s prosecution. Castille
had been elected to a seat on the State Supreme Court and
was serving as its chief justice. Williams filed a response
to the Commonwealth’s application. The disclosure of the
trial prosecutor’s sentencing memorandum in the PCRA
proceedings had alerted Williams to Chief Justice Cas-
tille’s involvement in the decision to seek a death sentence
in his case. For this reason, Williams also filed a motion
asking Chief Justice Castille to recuse himself or, if he
declined to do so, to refer the recusal motion to the full
court for decision. The Commonwealth opposed Williams’s
recusal motion. Without explanation, Chief Justice Cas-
tille denied the motion for recusal and the request for its
referral. Two days later, the Pennsylvania Supreme Court
denied the application to vacate the stay and ordered full
briefing on the issues raised in the appeal. The State
Supreme Court then vacated the PCRA court’s order
granting penalty-phase relief and reinstated Williams’s
death sentence. Chief Justice Castille and Justices Baer
and Stevens joined the majority opinion written by Justice
Eakin. Justices Saylor and Todd concurred in the result
without issuing a separate opinion. See ___ Pa. ___, ___,
105 A. 3d 1234, 1245 (2014).
   Chief Justice Castille authored a concurrence. He la-
mented that the PCRA court had “lost sight of its role as a
neutral judicial officer” and had stayed Williams’s execu-
tion “for no valid reason.” Id., at ___, 105 A. 3d, at 1245.
“[B]efore condemning officers of the court,” the chief jus-
                 Cite as: 579 U. S. ____ (2016)           5

                     Opinion of the Court

tice stated, “the tribunal should be aware of the substan-
tive status of Brady law,” which he believed the PCRA
court had misapplied. Id., at ___, 105 A. 3d, at 1246. In
addition, Chief Justice Castille denounced what he per-
ceived as the “obstructionist anti-death penalty agenda” of
Williams’s attorneys from the Federal Community De-
fender Office. Ibid. PCRA courts “throughout Pennsylva-
nia need to be vigilant and circumspect when it comes to
the activities of this particular advocacy group,” he wrote,
lest Defender Office lawyers turn postconviction proceed-
ings “into a circus where [they] are the ringmasters, with
their parrots and puppets as a sideshow.” Id., at ___, 105
A. 3d, at 1247.
   Two weeks after the Pennsylvania Supreme Court
decided Williams’s case, Chief Justice Castille retired from
the bench. This Court granted Williams’s petition for
certiorari. 576 U. S. ___ (2015).
                             II

                             A

  Williams contends that Chief Justice Castille’s decision
as district attorney to seek a death sentence against him
barred the chief justice from later adjudicating Williams’s
petition to overturn that sentence. Chief Justice Castille,
Williams argues, violated the Due Process Clause of the
Fourteenth Amendment by acting as both accuser and
judge in his case.
  The Court’s due process precedents do not set forth a
specific test governing recusal when, as here, a judge had
prior involvement in a case as a prosecutor. For the rea-
sons explained below, however, the principles on which
these precedents rest dictate the rule that must control in
the circumstances here. The Court now holds that under
the Due Process Clause there is an impermissible risk of
actual bias when a judge earlier had significant, personal
involvement as a prosecutor in a critical decision regard-
6               WILLIAMS v. PENNSYLVANIA

                     Opinion of the Court

ing the defendant’s case.
   Due process guarantees “an absence of actual bias” on
the part of a judge. In re Murchison, 349 U. S. 133, 136
(1955). Bias is easy to attribute to others and difficult to
discern in oneself. To establish an enforceable and work-
able framework, the Court’s precedents apply an objective
standard that, in the usual case, avoids having to deter-
mine whether actual bias is present. The Court asks not
whether a judge harbors an actual, subjective bias, but
instead whether, as an objective matter, “the average
judge in his position is ‘likely’ to be neutral, or whether
there is an unconstitutional ‘potential for bias.’ ” Caper-
ton, 556 U. S., at 881. Of particular relevance to the in-
stant case, the Court has determined that an unconstitu-
tional potential for bias exists when the same person
serves as both accuser and adjudicator in a case. See
Murchison, 349 U. S., at 136–137. This objective risk of
bias is reflected in the due process maxim that “no man
can be a judge in his own case and no man is permitted to
try cases where he has an interest in the outcome.” Id., at
136.
   The due process guarantee that “no man can be a judge
in his own case” would have little substance if it did not
disqualify a former prosecutor from sitting in judgment of
a prosecution in which he or she had made a critical deci-
sion. This conclusion follows from the Court’s analysis in
In re Murchison. That case involved a “one-man judge-
grand jury” proceeding, conducted pursuant to state law,
in which the judge called witnesses to testify about sus-
pected crimes. Id., at 134. During the course of the exam-
inations, the judge became convinced that two witnesses
were obstructing the proceeding. He charged one witness
with perjury and then, a few weeks later, tried and con-
victed him in open court. The judge charged the other
witness with contempt and, a few days later, tried and
convicted him as well. This Court overturned the convic-
                 Cite as: 579 U. S. ____ (2016)           7

                     Opinion of the Court

tions on the ground that the judge’s dual position as ac-
cuser and decisionmaker in the contempt trials violated
due process: “Having been a part of [the accusatory] pro-
cess a judge cannot be, in the very nature of things, wholly
disinterested in the conviction or acquittal of those ac-
cused.” Id., at 137.
   No attorney is more integral to the accusatory process
than a prosecutor who participates in a major adversary
decision. When a judge has served as an advocate for the
State in the very case the court is now asked to adjudicate,
a serious question arises as to whether the judge, even
with the most diligent effort, could set aside any personal
interest in the outcome. There is, furthermore, a risk that
the judge “would be so psychologically wedded” to his or
her previous position as a prosecutor that the judge
“would consciously or unconsciously avoid the appearance
of having erred or changed position.” Withrow, 421 U. S.,
at 57. In addition, the judge’s “own personal knowledge
and impression” of the case, acquired through his or her
role in the prosecution, may carry far more weight with
the judge than the parties’ arguments to the court. Mur-
chison, supra, at 138; see also Caperton, supra, at 881.
   Pennsylvania argues that Murchison does not lead to
the rule that due process requires disqualification of a
judge who, in an earlier role as a prosecutor, had signifi-
cant involvement in making a critical decision in the case.
The facts of Murchison, it should be acknowledged, differ
in many respects from a case like this one. In Murchison,
over the course of several weeks, a single official (the so-
called judge-grand jury) conducted an investigation into
suspected crimes; made the decision to charge witnesses
for obstruction of that investigation; heard evidence on the
charges he had lodged; issued judgments of conviction; and
imposed sentence. See 349 U. S., at 135 (petitioners ob-
jected to “trial before the judge who was at the same time
the complainant, indicter and prosecutor”). By contrast, a
8               WILLIAMS v. PENNSYLVANIA

                     Opinion of the Court

judge who had an earlier involvement in a prosecution
might have been just one of several prosecutors working
on the case at each stage of the proceedings; the prosecu-
tor’s immediate role might have been limited to a particu-
lar aspect of the prosecution; and decades might have
passed before the former prosecutor, now a judge, is called
upon to adjudicate a claim in the case.
   These factual differences notwithstanding, the constitu-
tional principles explained in Murchison are fully applica-
ble where a judge had a direct, personal role in the de-
fendant’s prosecution. The involvement of other actors
and the passage of time are consequences of a complex
criminal justice system, in which a single case may be
litigated through multiple proceedings taking place over a
period of years. This context only heightens the need for
objective rules preventing the operation of bias that oth-
erwise might be obscured. Within a large, impersonal
system, an individual prosecutor might still have an influ-
ence that, while not so visible as the one-man grand jury
in Murchison, is nevertheless significant. A prosecutor
may bear responsibility for any number of critical deci-
sions, including what charges to bring, whether to extend
a plea bargain, and which witnesses to call. Even if dec-
ades intervene before the former prosecutor revisits the
matter as a jurist, the case may implicate the effects and
continuing force of his or her original decision. In these
circumstances, there remains a serious risk that a judge
would be influenced by an improper, if inadvertent, motive
to validate and preserve the result obtained through the
adversary process. The involvement of multiple actors
and the passage of time do not relieve the former prosecu-
tor of the duty to withdraw in order to ensure the neutral-
ity of the judicial process in determining the consequences
that his or her own earlier, critical decision may have set
in motion.
                 Cite as: 579 U. S. ____ (2016)            9

                     Opinion of the Court

                               B
   This leads to the question whether Chief Justice Cas-
tille’s authorization to seek the death penalty against
Williams amounts to significant, personal involvement in
a critical trial decision. The Court now concludes that it
was a significant, personal involvement; and, as a result,
Chief Justice Castille’s failure to recuse from Williams’s
case presented an unconstitutional risk of bias.
   As an initial matter, there can be no doubt that the
decision to pursue the death penalty is a critical choice in
the adversary process. Indeed, after a defendant is
charged with a death-eligible crime, whether to ask a jury
to end the defendant’s life is one of the most serious dis-
cretionary decisions a prosecutor can be called upon to
make.
   Nor is there any doubt that Chief Justice Castille had a
significant role in this decision. Without his express
authorization, the Commonwealth would not have been
able to pursue a death sentence against Williams. The
importance of this decision and the profound consequences
it carries make it evident that a responsible prosecutor
would deem it to be a most significant exercise of his or
her official discretion and professional judgment.
   Pennsylvania nonetheless contends that Chief Justice
Castille in fact did not have significant involvement in the
decision to seek a death sentence against Williams. The
chief justice, the Commonwealth points out, was the head
of a large district attorney’s office in a city that saw many
capital murder trials. Tr. of Oral Arg. 36. According to
Pennsylvania, his approval of the trial prosecutor’s re-
quest to pursue capital punishment in Williams’s case
amounted to a brief administrative act limited to “the time
it takes to read a one-and-a-half-page memo.” Ibid. In
this Court’s view, that characterization cannot be credited.
The Court will not assume that then-District Attorney
Castille treated so major a decision as a perfunctory task
10              WILLIAMS v. PENNSYLVANIA

                     Opinion of the Court

requiring little time, judgment, or reflection on his part.
   Chief Justice Castille’s own comments while running for
judicial office refute the Commonwealth’s claim that he
played a mere ministerial role in capital sentencing deci-
sions. During the chief justice’s election campaign, multi-
ple news outlets reported his statement that he “sent 45
people to death rows” as district attorney. Seelye, Castille
Keeps His Cool in Court Run, Philadelphia Inquirer, Apr.
30, 1993, p. B1; see also, e.g., Brennan, State Voters Must
Choose Next Supreme Court Member, Legal Intelligencer,
Oct. 28, 1993, pp. 1, 12. Chief Justice Castille’s willing-
ness to take personal responsibility for the death sentences
obtained during his tenure as district attorney indicate
that, in his own view, he played a meaningful role in those
sentencing decisions and considered his involvement to be
an important duty of his office.
   Although not necessary to the disposition of this case,
the PCRA court’s ruling underscores the risk of permitting
a former prosecutor to be a judge in what had been his or
her own case. The PCRA court determined that the trial
prosecutor—Chief Justice Castille’s former subordinate in
the district attorney’s office—had engaged in multiple,
intentional Brady violations during Williams’s prosecu-
tion. App. 131–145, 150–154. While there is no indication
that Chief Justice Castille was aware of the alleged prose-
cutorial misconduct, it would be difficult for a judge in his
position not to view the PCRA court’s findings as a criti-
cism of his former office and, to some extent, of his own
leadership and supervision as district attorney.
   The potential conflict of interest posed by the PCRA
court’s findings illustrates the utility of statutes and
professional codes of conduct that “provide more protection
than due process requires.” Caperton, 556 U. S., at 890. It
is important to note that due process “demarks only the
outer boundaries of judicial disqualifications.” Aetna Life
Ins. Co. v. Lavoie, 475 U. S. 813, 828 (1986). Most ques-
                 Cite as: 579 U. S. ____ (2016)           11

                     Opinion of the Court

tions of recusal are addressed by more stringent and
detailed ethical rules, which in many jurisdictions already
require disqualification under the circumstances of this
case. See Brief for American Bar Association as Amicus
Curiae 5, 11–14; see also ABA Model Code of Judicial
Conduct Rules 2.11(A)(1), (A)(6)(b) (2011) (no judge may
participate “in any proceeding in which the judge’s impar-
tiality might reasonably be questioned,” including where
the judge “served in governmental employment, and in
such capacity participated personally and substantially as
a lawyer or public official concerning the proceeding”);
ABA Center for Professional Responsibility Policy Imple-
mentation Comm., Comparison of ABA Model Judicial
Code and State Variations (Dec. 14, 2015), available at
http://www.americanbar.org/content/dam/aba/administrative/
professional_responsibility/2_11.authcheckdam.pdf (as last
visited June 7, 2016) (28 States have adopted language
similar to ABA Model Judicial Code Rule 2.11); 28 U. S. C.
§455(b)(3) (recusal required where judge “has served in
governmental employment and in such capacity partici-
pated as counsel, adviser or material witness concerning
the proceeding”). At the time Williams filed his recusal
motion with the Pennsylvania Supreme Court, for exam-
ple, Pennsylvania’s Code of Judicial Conduct disqualified
judges from any proceeding in which “they served as a
lawyer in the matter in controversy, or a lawyer with
whom they previously practiced law served during such
association as a lawyer concerning the matter. . . .” Pa.
Code of Judicial Conduct, Canon 3C (1974, as amended).
The fact that most jurisdictions have these rules in place
suggests that today’s decision will not occasion a signifi-
cant change in recusal practice.
   Chief Justice Castille’s significant, personal involvement
in a critical decision in Williams’s case gave rise to an
unacceptable risk of actual bias. This risk so endangered
the appearance of neutrality that his participation in the
12              WILLIAMS v. PENNSYLVANIA

                      Opinion of the Court

case “must be forbidden if the guarantee of due process is
to be adequately implemented.” Withrow, 421 U. S., at 47.
                             III
   Having determined that Chief Justice Castille’s partici-
pation violated due process, the Court must resolve
whether Williams is entitled to relief. In past cases, the
Court has not had to decide the question whether a due
process violation arising from a jurist’s failure to recuse
amounts to harmless error if the jurist is on a multimem-
ber court and the jurist’s vote was not decisive. See La-
voie, supra, at 827–828 (addressing “the question whether
a decision of a multimember tribunal must be vacated
because of the participation of one member who had an
interest in the outcome of the case,” where that member’s
vote was outcome determinative). For the reasons dis-
cussed below, the Court holds that an unconstitutional
failure to recuse constitutes structural error even if the
judge in question did not cast a deciding vote.
   The Court has little trouble concluding that a due pro-
cess violation arising from the participation of an inter-
ested judge is a defect “not amenable” to harmless-error
review, regardless of whether the judge’s vote was disposi-
tive. Puckett v. United States, 556 U. S. 129, 141 (2009)
(emphasis deleted). The deliberations of an appellate
panel, as a general rule, are confidential. As a result, it is
neither possible nor productive to inquire whether the
jurist in question might have influenced the views of his or
her colleagues during the decisionmaking process. Indeed,
one purpose of judicial confidentiality is to assure jurists
that they can reexamine old ideas and suggest new ones,
while both seeking to persuade and being open to persua-
sion by their colleagues. As Justice Brennan wrote in his
Lavoie concurrence,
     “The description of an opinion as being ‘for the court’
     connotes more than merely that the opinion has been
                 Cite as: 579 U. S. ____ (2016)           13

                     Opinion of the Court

    joined by a majority of the participating judges. It re-
    flects the fact that these judges have exchanged ideas
    and arguments in deciding the case. It reflects the
    collective process of deliberation which shapes the
    court’s perceptions of which issues must be addressed
    and, more importantly, how they must be addressed.
    And, while the influence of any single participant in
    this process can never be measured with precision,
    experience teaches us that each member’s involve-
    ment plays a part in shaping the court’s ultimate dis-
    position.” 475 U. S., at 831.
   These considerations illustrate, moreover, that it does
not matter whether the disqualified judge’s vote was
necessary to the disposition of the case. The fact that the
interested judge’s vote was not dispositive may mean only
that the judge was successful in persuading most members
of the court to accept his or her position. That outcome
does not lessen the unfairness to the affected party. See
id., at 831–832 (Blackmun, J., concurring in judgment).
   A multimember court must not have its guarantee of
neutrality undermined, for the appearance of bias de-
means the reputation and integrity not just of one jurist,
but of the larger institution of which he or she is a part.
An insistence on the appearance of neutrality is not some
artificial attempt to mask imperfection in the judicial
process, but rather an essential means of ensuring the
reality of a fair adjudication. Both the appearance and
reality of impartial justice are necessary to the public
legitimacy of judicial pronouncements and thus to the rule
of law itself. When the objective risk of actual bias on the
part of a judge rises to an unconstitutional level, the fail-
ure to recuse cannot be deemed harmless.
   The Commonwealth points out that ordering a rehear-
ing before the Pennsylvania Supreme Court may not
provide complete relief to Williams because judges who
14              WILLIAMS v. PENNSYLVANIA

                     Opinion of the Court

were exposed to a disqualified judge may still be influ-
enced by their colleague’s views when they rehear the
case. Brief for Respondent 51, 62. An inability to guaran-
tee complete relief for a constitutional violation, however,
does not justify withholding a remedy altogether. Allow-
ing an appellate panel to reconsider a case without the
participation of the interested member will permit judges
to probe lines of analysis or engage in discussions
they may have felt constrained to avoid in their first
deliberations.
  Chief Justice Castille’s participation in Williams’s case
was an error that affected the State Supreme Court’s
whole adjudicatory framework below. Williams must be
granted an opportunity to present his claims to a court
unburdened by any “possible temptation . . . not to hold
the balance nice, clear and true between the State and the
accused.” Tumey v. Ohio, 273 U. S. 510, 532 (1927).
                          *    *    *
  Where a judge has had an earlier significant, personal
involvement as a prosecutor in a critical decision in the
defendant’s case, the risk of actual bias in the judicial
proceeding rises to an unconstitutional level. Due process
entitles Terrance Williams to “a proceeding in which he
may present his case with assurance” that no member of
the court is “predisposed to find against him.” Marshall v.
Jerrico, Inc., 446 U. S. 238, 242 (1980).
  The judgment of the Supreme Court of Pennsylvania is
vacated, and the case is remanded for further proceedings
not inconsistent with this opinion.
                                            It is so ordered.
                 Cite as: 579 U. S. ____ (2016)            1

                   ROBERTS, C. J., dissenting

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 15–5040
                         _________________


        TERRANCE WILLIAMS, PETITIONER v.

                PENNSYLVANIA

    ON WRIT OF CERTIORARI TO THE SUPREME COURT OF 

           PENNSYLVANIA, EASTERN DISTRICT

                        [June 9, 2016]

   CHIEF JUSTICE ROBERTS, with whom JUSTICE ALITO
joins, dissenting.
   In 1986, Ronald Castille, then District Attorney of Phil-
adelphia, authorized a prosecutor in his office to seek the
death penalty against Terrance Williams. Almost 30
years later, as Chief Justice of the Pennsylvania Supreme
Court, he participated in deciding whether Williams’s fifth
habeas petition—which raised a claim unconnected to the
prosecution’s decision to seek the death penalty—could be
heard on the merits or was instead untimely. This Court
now holds that because Chief Justice Castille made a
“critical” decision as a prosecutor in Williams’s case, there
is a risk that he “would be so psychologically wedded” to
his previous decision that it would violate the Due Process
Clause for him to decide the distinct issues raised in the
habeas petition. Ante, at 6–7 (internal quotation marks
omitted). According to the Court, that conclusion follows
from the maxim that “no man can be a judge in his own
case.” Ante, at 6 (internal quotation marks omitted).
   The majority opinion rests on proverb rather than prec-
edent. This Court has held that there is “a presumption of
honesty and integrity in those serving as adjudicators.”
Withrow v. Larkin, 421 U. S. 35, 47 (1975). To overcome
that presumption, the majority relies on In re Murchison,
349 U. S. 133 (1955). We concluded there that the Due
2               WILLIAMS v. PENNSYLVANIA

                   ROBERTS, C. J., dissenting

Process Clause is violated when a judge adjudicates the
same question—based on the same facts—that he had
already considered as a grand juror in the same case.
Here, however, Williams does not allege that Chief Justice
Castille had any previous knowledge of the contested facts
at issue in the habeas petition, or that he had previously
made any decision on the questions raised by that petition.
I would accordingly hold that the Due Process Clause did
not require Chief Justice Castille’s recusal.
                                I
   In 1986, petitioner Terrance Williams stood trial for the
murder of Amos Norwood. Prosecutors believed that
Williams and his friend Marc Draper had asked Norwood
for a ride, directed him to a cemetery, and then beat him
to death with a tire iron after robbing him. Andrea Foulkes,
the Philadelphia Assistant District Attorney prosecut-
ing the case, prepared a one-and-a-half page memo for her
superiors—Homicide Unit Chief Mark Gottlieb and Dis-
trict Attorney Ronald Castille—“request[ing] that we
actively seek the death penalty.” App. 424a. The memo
briefly described the facts of the case and Williams’s prior
felonies, including a previous murder conviction. Gottlieb
read the memo and then passed it to Castille with a note
recommending the death penalty. Id., at 426a. Castille
wrote at the bottom of the memo, “Approved to proceed on
the death penalty,” and signed his name. Ibid.
   At trial, Williams testified that he had never met Nor-
wood and that someone else must have murdered him.
After hearing extensive evidence linking Williams to the
crime, the jury convicted him of murder and sentenced
him to death. 524 Pa. 218, 227, 570 A. 2d 75, 79–80
(1990).
   In 1995, Williams filed a habeas petition in Pennsylva-
nia state court, alleging that his trial counsel had been
ineffective for failing to present mitigating evidence of his
                 Cite as: 579 U. S. ____ (2016)           3

                  ROBERTS, C. J., dissenting

childhood sexual abuse, among other claims. At a hearing
related to that petition, Williams acknowledged that he
knew Norwood and claimed that Norwood had sexually
abused him. ___ Pa. ___, ___, 105 A. 3d 1234, 1240 (2014).
The petition was denied. Williams filed two more state
habeas petitions, which were both dismissed as untimely,
and a federal habeas petition, which was also denied. See
Williams v. Beard, 637 F. 3d 195, 238 (CA3 2011).
  This case arises out of Williams’s fifth habeas petition,
which he filed in state court in 2012. In that petition,
Williams argued that he was entitled to a new sentencing
proceeding because the prosecution at trial had failed to
turn over certain evidence suggesting that “Norwood was
sexually involved with boys around [Williams’s] age at the
time of his murder.” Crim. No. CP–51–CR–0823621–1984
(Phila. Ct. Common Pleas, Nov. 27, 2012), App. 80a.
  It is undisputed that Williams’s fifth habeas petition is
untimely under Pennsylvania law. In order to overcome
that time bar, Pennsylvania law required Williams to
show that “(1) the failure to previously raise [his] claim
was the result of interference by government officials and
(2) the information on which he relies could not have been
obtained earlier with the exercise of due diligence.” ___
Pa., at ___, 105 A. 3d, at 1240. The state habeas court
held that Williams met that burden because “the govern-
ment withheld multiple statements from [Williams’s] trial
counsel, all of which strengthened the inference that Amos
Norwood was sexually inappropriate with a number of
teenage boys,” and Williams was unable to access those
statements until an evidentiary proceeding ordered by the
court. App. 95a.
  The Commonwealth appealed to the Pennsylvania
Supreme Court, and Williams filed a motion requesting
that Chief Justice Castille recuse himself on the ground
that he had “personally authorized his Office to seek the
death penalty” nearly 30 years earlier. Id., at 181a (em-
4               WILLIAMS v. PENNSYLVANIA

                   ROBERTS, C. J., dissenting

phasis deleted). Chief Justice Castille summarily denied
the recusal motion, and the six-member Pennsylvania
Supreme Court proceeded to hear the case. The court
unanimously reinstated Williams’s sentence.
  According to the Pennsylvania Supreme Court, Williams
failed to make the threshold showing necessary to over-
come the time bar because there was “abundant evidence”
that Williams “knew of Norwood’s homosexuality and
conduct with teenage boys well before trial, sufficient to
present [Norwood] as unsympathetic before the jury.” ___
Pa., at ___, 105 A. 3d, at 1241. The court pointed out that
Williams was, of course, personally aware of Norwood’s
abuse and could have raised the issue at trial, but instead
chose to disclaim having ever met Norwood. The court
also noted that Williams had raised similar claims of
abuse in his first state habeas proceeding. Ibid. Chief
Justice Castille concurred separately, criticizing the lower
court for failing to dismiss Williams’s petition as “time-
barred and frivolous.” Id., at ___, 105 A. 3d, at 1245.
                               II

                               A

  In the context of a criminal proceeding, the Due Process
Clause requires States to adopt those practices that are
fundamental to principles of liberty and justice, and which
inhere “in the very idea of free government” and are “the
inalienable right of a citizen of such a government.” Twin-
ing v. New Jersey, 211 U. S. 78, 106 (1908). A fair trial
and appeal is one such right. See Lisenba v. California,
314 U. S. 219, 236 (1941); Aetna Life Ins. Co. v. Lavoie,
475 U. S. 813, 825 (1986). In ensuring that right, “it is
normally within the power of the State to regulate proce-
dures under which its laws are carried out,” unless a
procedure “offends some principle of justice so rooted in
the traditions and conscience of our people as to be ranked
as fundamental.” Id., at 821 (internal quotation marks
                  Cite as: 579 U. S. ____ (2016)            5

                   ROBERTS, C. J., dissenting

omitted).
   It is clear that a judge with “a direct, personal, substan-
tial, pecuniary interest” in a case may not preside over
that case. Tumey v. Ohio, 273 U. S. 510, 523 (1927). We
have also held that a judge may not oversee a criminal
contempt proceeding where the judge has previously
served as grand juror in the same case, or where the party
charged with contempt has conducted “an insulting attack
upon the integrity of the judge carrying such potential for
bias as to require disqualification.” Mayberry v. Pennsyl-
vania, 400 U. S. 455, 465–466 (1971) (internal quotation
marks omitted); see Murchison, 349 U. S., at 139.
   Prior to this Court’s decision in Caperton v. A. T. Massey
Coal Co., 556 U. S. 868 (2009), we had declined to require
judicial recusal under the Due Process Clause beyond
those defined situations. In Caperton, however, the Court
adopted a new standard that requires recusal “when the
probability of actual bias on the part of the judge or deci-
sionmaker is too high to be constitutionally tolerable.” Id.,
at 872 (internal quotation marks omitted). The Court
framed the inquiry as “whether, under a realistic appraisal
of psychological tendencies and human weakness, the
interest poses such a risk of actual bias or prejudgment
that the practice must be forbidden if the guarantee of due
process is to be adequately implemented.” Id., at 883–884
(internal quotation marks omitted).
                             B
   According to the majority, the Due Process Clause re-
quired Chief Justice Castille’s recusal because he had
“significant, personal involvement in a critical trial deci-
sion” in Williams’s case. Ante, at 9. Otherwise, the major-
ity explains, there is “an unacceptable risk of actual bias.”
Ante, at 11. In the majority’s view, “[t]his conclusion
follows from the Court’s analysis in In re Murchison.”
Ante, at 6. But Murchison does not support the majority’s
6               WILLIAMS v. PENNSYLVANIA

                   ROBERTS, C. J., dissenting

new rule—far from it.
   Murchison involved a peculiar Michigan law that au-
thorized the same person to sit as both judge and “one-
man grand jury” in the same case. 349 U. S., at 133 (in-
ternal quotation marks omitted). Pursuant to that law, a
Michigan judge—serving as grand jury—heard testimony
from two witnesses in a corruption case. The testimony
“persuaded” the judge that one of the witnesses “had
committed perjury”; the second witness refused to answer
questions. Id., at 134–135. The judge accordingly charged
the witnesses with criminal contempt, presided over the
trial, and convicted them. Ibid. We reversed, holding that
the trial had violated the Due Process Clause. Id., at 139.
   The Court today, acknowledging that Murchison “dif-
fer[s] in many respects from a case like this one,” ante, at
7, earns full marks for understatement. The Court in fact
fails to recognize the differences that are critical.
   First, Murchison found a due process violation because
the judge (sitting as grand jury) accused the witnesses of
contempt, and then (sitting as judge) presided over their
trial on that charge. As a result, the judge had made up
his mind about the only issue in the case before the trial
had even begun. We held that such prejudgment violated
the Due Process Clause. 349 U. S., at 137.
   Second, Murchison expressed concern that the judge’s
recollection of the testimony he had heard as grand juror
was “likely to weigh far more heavily with him than any
testimony given” at trial. Id., at 138. For that reason, the
Court found that the judge was at risk of calling “on his
own personal knowledge and impression of what had
occurred in the grand jury room,” rather than the evidence
presented to him by the parties. Ibid.
   Neither of those due process concerns is present here.
Chief Justice Castille was involved in the decision to seek
the death penalty, and perhaps it would be reasonable
under Murchison to require him to recuse himself from
                 Cite as: 579 U. S. ____ (2016)           7

                  ROBERTS, C. J., dissenting

any challenge casting doubt on that recommendation. But
that is not this case.
   This case is about whether Williams may overcome the
procedural bar on filing an untimely habeas petition,
which required him to show that the government inter-
fered with his ability to raise his habeas claim, and that
“the information on which he relies could not have been
obtained earlier with the exercise of due diligence.” ___
Pa., at ___, 105 A. 3d, at 1240. Even if Williams were to
overcome the timeliness bar, moreover, the only claim he
sought to raise on the merits was that the prosecution had
failed to turn over certain evidence at trial. The problem
in Murchison was that the judge, having been “part of the
accusatory process” regarding the guilt or innocence of the
defendants, could not then be “wholly disinterested” when
called upon to decide that very same issue. 349 U. S., at
137. In this case, in contrast, neither the procedural
question nor Williams’s merits claim in any way concerns
the pretrial decision to seek the death penalty.
   It is abundantly clear that, unlike in Murchison, Chief
Justice Castille had not made up his mind about either the
contested evidence or the legal issues under review in
Williams’s fifth habeas petition. How could he have?
Neither the contested evidence nor the legal issues were
ever before him as prosecutor. The one-and-a-half page
memo prepared by Assistant District Attorney Foulkes in
1986 did not discuss the evidence that Williams claims
was withheld by the prosecution at trial. It also did not
discuss Williams’s allegation that Norwood sexually
abused young men. It certainly did not discuss whether
Williams could have obtained that evidence of abuse ear-
lier through the exercise of due diligence.
   Williams does not assert that Chief Justice Castille had
any prior knowledge of the alleged failure of the prosecu-
tion to turn over such evidence, and he does not argue that
Chief Justice Castille had previously made any decision
8               WILLIAMS v. PENNSYLVANIA

                  ROBERTS, C. J., dissenting

with respect to that evidence in his role as prosecutor.
Even assuming that Chief Justice Castille remembered
the contents of the memo almost 30 years later—which is
doubtful—the memo could not have given Chief Justice
Castille any special “impression” of facts or issues not
raised in that memo. Id., at 138.
   The majority attempts to justify its rule based on the
“risk” that a judge “would be so psychologically wedded to
his or her previous position as a prosecutor that the judge
would consciously or unconsciously avoid the appearance
of having erred or changed position.” Ante, at 7 (internal
quotation marks omitted). But as a matter of simple logic,
nothing about how Chief Justice Castille might rule on
Williams’s fifth habeas petition would suggest that the
judge had erred or changed his position on the distinct
question whether to seek the death penalty prior to trial.
In sum, there was not such an “objective risk of actual
bias,” ante, at 13, that it was fundamentally unfair for
Chief Justice Castille to participate in the decision of an
issue having nothing to do with his prior participation in
the case.
                         *   *     *
  The Due Process Clause did not prohibit Chief Justice
Castille from hearing Williams’s case. That does not
mean, however, that it was appropriate for him to do so.
Williams cites a number of state court decisions and ethics
opinions that prohibit a prosecutor from later serving as
judge in a case that he has prosecuted. Because the Due
Process Clause does not mandate recusal in cases such as
this, it is up to state authorities—not this Court—to de-
termine whether recusal should be required.
  I would affirm the judgment of the Pennsylvania Su-
preme Court, and respectfully dissent from the Court’s
contrary conclusion.
                  Cite as: 579 U. S. ____ (2016)            1

                     THOMAS, J., dissenting

SUPREME COURT OF THE UNITED STATES
                          _________________

                          No. 15–5040
                          _________________


        TERRANCE WILLIAMS, PETITIONER v.

                PENNSYLVANIA

    ON WRIT OF CERTIORARI TO THE SUPREME COURT OF 

           PENNSYLVANIA, EASTERN DISTRICT

                         [June 9, 2016]

   JUSTICE THOMAS, dissenting.
   The Court concludes that it violates the Due Process
Clause for the chief justice of the Supreme Court of Penn-
sylvania, a former district attorney who was not the trial
prosecutor in petitioner Terrance Williams’ case, to review
Williams’ fourth petition for state postconviction review.
Ante, at 8–9, 14. That conclusion is flawed. The specter of
bias alone in a judicial proceeding is not a deprivation of
due process. Rather than constitutionalize every judicial
disqualification rule, the Court has left such rules to legis-
latures, bar associations, and the judgment of individual
adjudicators. Williams, moreover, is not a criminal de-
fendant. His complaint is instead that the due process
protections in his state postconviction proceedings—an
altogether new civil matter, not a continuation of his
criminal trial—were lacking. Ruling in Williams’ favor,
the Court ignores this posture and our precedents com-
manding less of state postconviction proceedings than of
criminal prosecutions involving defendants whose convic-
tions are not yet final. I respectfully dissent.
                             I
  A reader of the majority opinion might mistakenly think
that the prosecution against Williams is ongoing, for the
majority makes no mention of the fact that Williams’
2                WILLIAMS v. PENNSYLVANIA

                     THOMAS, J., dissenting

sentence has been final for more than 25 years. Because
the postconviction posture of this case is of crucial im-
portance in considering the question presented, I begin
with the protracted procedural history of Williams’ repeated
attempts to collaterally attack his sentence.
                              A
  Thirty-two years ago, Williams and his accomplice beat
their victim to death with a tire iron and a socket wrench.
Commonwealth v. Williams, 524 Pa. 218, 222–224, 570
A. 2d 75, 77–78 (1990) (Williams I ). Williams later re-
turned to the scene of the crime, a cemetery, soaked the
victim’s body in gasoline, and set it on fire. Id., at 224,
570 A. 2d, at 78. After the trial against Williams com-
menced, both the Chief of the Homicide Unit and the
District Attorney, Ronald Castille, approved the trial
prosecutor’s decision to seek the death penalty by signing
a piece of paper. See App. 426. That was Castille’s only
involvement in Williams’ criminal case. Thereafter, a
Pennsylvania jury convicted Williams of first-degree mur-
der, and he was sentenced to death. Williams I, 524 Pa.,
at 221–222, 570 A. 2d, at 77. The Supreme Court of Penn-
sylvania affirmed his conviction and sentence. Id., at 235,
570 A. 2d, at 84.
  Five years later, Williams filed his first petition for state
postconviction relief. Commonwealth v. Williams, 581 Pa.
57, 65, 863 A. 2d 505, 509 (2004) (Williams II ). The post-
conviction court denied the petition. Id., at 65, 863 A. 2d,
at 510. Williams appealed, raising 23 alleged errors. Ibid.
The Supreme Court of Pennsylvania, which included
Castille in his new capacity as a justice of that court,
affirmed the denial of relief. Id., at 88, 863 A. 2d, at 523.
The court rejected some claims on procedural grounds and
denied the remaining claims on the merits. Id., at 68–88,
863 A. 2d, at 511–523. The court’s lengthy opinion did not
mention the possibility of Castille’s bias, and Williams
                     Cite as: 579 U. S. ____ (2016)                    3

                         THOMAS, J., dissenting

apparently never asked for his recusal.
   Then in 2005, Williams filed two more petitions for state
postconviction relief. Both petitions were dismissed as
untimely, and the Supreme Court of Pennsylvania af-
firmed. Commonwealth v. Williams, 589 Pa. 355, 909 A.
2d 297 (2006) ( per curiam) (Williams III ); Commonwealth
v. Williams, 599 Pa. 495, 962 A. 2d 609 (2009) (per curiam)
(Williams IV ). Castille also presumably participated in
those proceedings, but, again, Williams apparently did not
ask for him to recuse.1
   Williams then made a fourth attempt to vacate his
sentence in state court in 2012. ___ Pa. ___, ___, 105 A. 3d
1234, 1237 (2014) (Williams VI ). Williams alleged that
the prosecution violated Brady v. Maryland, 373 U. S. 83
(1963), by failing to disclose exculpatory evidence. The
allegedly exculpatory evidence was information about
Williams’ motive. According to Williams, the prosecution
should have disclosed to his counsel that it knew that
Williams and the victim had previously engaged in a
sexual relationship when Williams was a minor. Williams
VI, ___ Pa., at ___, 105 A. 3d, at 1237.2 The state postcon-
——————
  1 In 2005, Williams also filed a federal habeas petition, which the

federal courts ultimately rejected. Williams v. Beard, 637 F. 3d 195,
238 (CA3 2011) (Williams V ), cert. denied, Williams v. Wetzel, 567 U. S.
___ (2012).
  2 Setting aside how a prosecutor could violate Brady by failing to

disclose information to the defendant about the defendant’s motive to
kill, it is worth noting that this allegation merely repackaged old
arguments. During a state postconviction hearing in 1998, Williams
had presented evidence of his prior sexual abuse, including “multiple
sexual victimizations (including sodomy) during his childhood,” to
support his ineffective assistance claim. Williams II, 581 Pa. 57, 98,
863 A. 2d 505, 530 (2004) (Saylor, J., dissenting). And he had “argued
[that the victim] engaged in homosexual acts with him.” Williams VI,
__ Pa., at ___, 105 A. 3d, at 1236. Then, in his federal habeas proceed-
ings, Williams admitted that his plan on the night of the murder was to
threaten to reveal to the victim’s wife that the victim was a homosex-
ual, and he contended that his attorney should have presented related
4                  WILLIAMS v. PENNSYLVANIA

                         THOMAS, J., dissenting

viction court agreed and vacated his sentence. Id., at ___,
105 A. 3d, at 1239.
   The Commonwealth appealed to the Supreme Court of
Pennsylvania. Only then—the fourth time that Williams
appeared before Castille—did Williams ask him to recuse.
App. 181. Castille denied the recusal motion and declined
to refer it to the full court. Id., at 171. Shortly thereafter,
the court vacated the postconviction court’s order and
reinstated Williams’ sentence. The court first noted that
Williams’ fourth petition “was filed over 20 years after
[Williams’] judgment of sentence became final” and “was
untimely on its face.” Williams VI, ___ Pa., at ___, 105
A. 3d, at 1239. The court rejected the trial court’s conclu-
sion that an exception to Pennsylvania’s timeliness rule
applied and reached “the inescapable conclusion that
[Williams] is not entitled to relief.” Id., at ___, 105 A. 3d,
at 1239–1241; see also id., at ___, 105 A. 3d, at 1245
(Castille, J., concurring) (writing separately “to address
the important responsibilities of the [state postconvic-
tion] trial courts in serial capital [state postconviction]
matters”).
   Finally, Williams filed an application for reargument.
App. 9. The court denied the application without Castille’s
participation. Id., at 8. Castille had retired from the
bench nearly two months before the court ruled.
                             B
  As this procedural history illustrates, the question
presented is hardly what the majority makes it out to be.
The majority incorrectly refers to the case before us and
Williams’ criminal case (that ended in 1990) as a decades-
long “single case” or “matter.” Ante, at 8; see also ante, at
7–9. The majority frames the issue as follows: whether

—————— 

evidence of the victim’s prior sexual relationship with him. Williams V, 

supra, at 200, 225–226, 229–230.

                  Cite as: 579 U. S. ____ (2016)            5

                     THOMAS, J., dissenting

the Due Process Clause permits Castille to “ac[t] as both
accuser and judge in [Williams’] case.” Ante, at 5. The
majority answers: “When a judge has served as an advo-
cate for the State in the very case the court is now asked to
adjudicate, a serious question arises as to whether the
judge, even with the most diligent effort, could set aside
any personal interest in the outcome.” Ante, at 7 (empha-
sis added). Accordingly, the majority holds that “[w]here a
judge has had an earlier significant, personal involvement
as a prosecutor in a critical decision in the defendant’s
case, the risk of actual bias in the judicial proceeding rises
to an unconstitutional level.” Ante, at 14 (emphasis added).
That is all wrong.
   There has been, however, no “single case” in which
Castille acted as both prosecutor and adjudicator. Castille
was still serving in the district attorney’s office when
Williams’ criminal proceedings ended and his sentence of
death became final. Williams’ filing of a petition for state
postconviction relief did not continue (or resurrect) that
already final criminal proceeding. A postconviction pro-
ceeding “is not part of the criminal proceeding itself ” but
“is in fact considered to be civil in nature,” Pennsylvania v.
Finley, 481 U. S. 551, 556–557 (1987), and brings with it
fewer procedural protections. See, e.g., District Attorney’s
Office for Third Judicial Dist. v. Osborne, 557 U. S. 52, 68
(2009).
   Williams’ case therefore presents a much different
question from that posited by the majority. It is more
accurately characterized as whether a judge may review a
petition for postconviction relief when that judge previ-
ously served as district attorney while the petitioner’s
criminal case was pending. For the reasons that follow,
that different question merits a different answer.
                           II
  The “settled usages and modes of proceeding existing in
6               WILLIAMS v. PENNSYLVANIA

                    THOMAS, J., dissenting

the common and statute law of England before the emi-
gration of our ancestors” are the touchstone of due process.
Tumey v. Ohio, 273 U. S. 510, 523 (1927); see also Mur­
ray’s Lessee v. Hoboken Land & Improvement Co., 18 How.
272, 277 (1856). What due process requires of the judicial
proceedings in the Pennsylvania postconviction courts,
therefore, is guided by the historical treatment of judicial
disqualification. And here, neither historical practice nor
this Court’s case law constitutionalizing that practice
requires a former prosecutor to recuse from a prisoner’s
postconviction proceedings.
                             A
   At common law, a fair tribunal meant that “no man
shall be a judge in his own case.” 1 E. Coke, Institutes of
the Laws of England §212, *141a (“[A]liquis non debet esse
judex in propiâ causâ”). That common-law conception of a
fair tribunal was a narrow one. A judge could not decide a
case in which he had a direct and personal financial stake.
For example, a judge could not reap the fine paid by a
defendant. See, e.g., Dr. Bonham’s Case, 8 Co. Rep. 107a,
114a, 118a, 77 Eng. Rep. 638, 647, 652 (C. P. 1610) (opin-
ing that a panel of adjudicators could not all at once serve
as “judges to give sentence or judgment; ministers to make
summons; and parties to have the moiety of the forfei-
ture”). Nor could he adjudicate a case in which he was a
party. See, e.g., Earl of Derby’s Case, 12 Co. Rep. 114, 77
Eng. Rep. 1390 (K. B. 1614). But mere bias—without any
financial stake in a case—was not grounds for disqualifi-
cation. The biases of judges “cannot be challenged,” ac-
cording to Blackstone, “[f ]or the law will not suppose a
possibility of bias or favour in a judge, who is already
sworn to administer impartial justice, and whose author-
ity greatly depends upon that presumption and idea.” 3 W.
Blackstone, Commentaries on the Laws of England, 361
(1768) (Blackstone); see also, e.g., Brookes v. Earl of Riv­
                  Cite as: 579 U. S. ____ (2016)             7

                     THOMAS, J., dissenting

ers, Hardres 503, 145 Eng. Rep. 569 (Exch. 1668) (deciding
that a judge’s “favour shall not be presumed” merely
because his brother-in-law was involved).
   The early American conception of judicial disqualifica-
tion was in keeping with the “clear and simple” common-
law rule—“a judge was disqualified for direct pecuniary
interest and for nothing else.” Frank, Disqualification of
Judges, 56 Yale L. J. 605, 609 (1947) (Frank); see also R.
Flamm, Judicial Disqualification: Recusal and Disqualifi-
cation of Judges §1.4, p. 7 (2d ed. 2007). Most jurisdictions
required judges to recuse when they stood to profit from
their involvement or, more broadly, when their property
was involved. See Moses v. Julian, 45 N. H. 52, 55–56
(1863); see also, e.g., Jim v. State, 3 Mo. 147, 155 (1832)
(deciding that a judge was unlawfully interested in a
criminal case in which his slave was the defendant). But
the judge’s pecuniary interest had to be directly implicated
in the case. See, e.g., Davis v. State, 44 Tex. 523, 524
(1876) (deciding that a judge, who was the victim of a
theft, was not disqualified in the prosecution of the theft);
see also T. Cooley, Constitutional Limitations 594 (7th ed.
1903) (rejecting a financial stake “so remote, trifling, and
insignificant that it may fairly be supposed to be incapable
of affecting the judgment”); Moses, supra, at 57 (“[A] credi-
tor, lessee, or debtor, may be judge in the case of his debtor,
landlord, or creditor, except in cases where the amount
of the party’s property involved in the suit is so great that
his ability to meet his engagements with the judge may
depend upon the success of his suit”); Inhabitants of Read­
ington Twp. Hunterdon County v. Dilley, 24 N. J. L. 209,
212–213 (N. J. 1853) (deciding that a judge, who had
previously been paid to survey the roadway at issue in the
case, was not disqualified).
   Shortly after the founding, American notions of judicial
disqualification expanded in important respects. Of par-
ticular relevance here, the National and State Legisla-
8               WILLIAMS v. PENNSYLVANIA

                    THOMAS, J., dissenting

tures enacted statutes and constitutional provisions that
diverged from the common law by requiring disqualifica-
tion when the judge had served as counsel for one of the
parties. The first federal recusal statute, for example,
required disqualification not only when the judge was
“concerned in interest,” but also when he “ha[d] been of
counsel for either party.” Act of May 8, 1792, §11, 1 Stat.
278–279. Many States followed suit by enacting similar
disqualification statutes or constitutional provisions ex-
panding the common-law rule. See, e.g., Wilks v. State, 27
Tex. App. 381, 385, 11 S. W. 415, 416 (1889); Fechheimer
v. Washington, 77 Ind. 366, 368 (1881) (per curiam);
Sjoberg v. Nordin, 26 Minn. 501, 503, 5 N. W. 677, 678
(1880); Whipple v. Saginaw Circuit Court Judge, 26 Mich.
342, 343 (1873); Mathis v. State, 50 Tenn. 127, 128 (1871);
but see Owings v. Gibson, 9 Ky. 515, 517–518 (1820) (de-
ciding that it was for the judge to choose whether he could
fairly adjudicate a case in which he had served as a lawyer
for the plaintiff in the same action). Courts applied this
expanded view of disqualification not only in cases involv-
ing judges who had previously served as counsel for pri-
vate parties but also for those who previously served as
former attorneys general or district attorneys. See, e.g.,
Terry v. State, 24 S. W. 510, 510–511 (Tex. Crim. App.
1893); Mathis, supra, at 128.
   This expansion was modest: disqualification was re-
quired only when the newly appointed judge had served as
counsel in the same case. In Carr v. Fife, 156 U. S. 494
(1895), for example, this Court rejected the argument that
a judge was required to recuse because he had previously
served as counsel for some of the defendants in another
matter. Id., at 497–498. The Court left it to the judge “to
decide for himself whether it was improper for him to sit
in trial of the suit.” Id., at 498. Likewise, in Taylor v.
Williams, 26 Tex. 583 (1863), the Supreme Court of Texas
acknowledged that a judge was not, “by the common law,
                 Cite as: 579 U. S. ____ (2016)           9

                    THOMAS, J., dissenting

disqualified from sitting in a cause in which he had been
of counsel” and concluded “that the fact that the presiding
judge had been of counsel in the case did not necessarily
render him interested in it.” Id., at 585–586. A fortiori,
the Texas court held, a judge was not “interested” in a case
“merely from his having been of counsel in another cause
involving the same title.” Id., at 586 (emphasis added);
see also The Richmond, 9 F. 863, 864 (CCED La. 1881)
(“The decisions, so far as I have been able to find, are
unanimous that ‘of counsel’ means ‘of counsel for a party
in that cause and in that controversy,’ and if either the
cause or controversy is not identical the disqualification
does not exist”); Wolfe v. Hines, 93 Ga. 329, 20 S. E. 322
(1894) (same); Cleghorn v. Cleghorn, 66 Cal. 309, 5 P. 516
(1885) (same).
   This limitation—that the same person must act as
counsel and adjudicator in the same case—makes good
sense. At least one of the State’s highest courts feared
that any broader rule would wreak havoc: “If the circum-
stance of the judge having been of counsel, for some par-
ties in some case involving some of the issues which had
been theretofore tried[,] disqualified him from acting in
every case in which any of those parties, or those issues
should be subsequently involved, the most eminent mem-
bers of the bar, would, by reason of their extensive profes-
sional relations and their large experience be rendered
ineligible, or useless as judges.” Blackburn v. Craufurd,
22 Md. 447, 459 (1864). Indeed, any broader rule would be
at odds with this Court’s historical practice. Past Justices
have decided cases involving their former clients in the
private sector or their former offices in the public sector.
See Frank 622–625. The examples are legion; chief among
them is Marbury v. Madison, 1 Cranch 137 (1803), in
which then–Secretary of State John Marshall sealed but
failed to deliver William Marbury’s commission and then,
as newly appointed Chief Justice, Marshall decided
10              WILLIAMS v. PENNSYLVANIA

                     THOMAS, J., dissenting

whether mandamus was an available remedy to require
James Madison to finish the job. See Paulsen, Marbury’s
Wrongness, 20 Constitutional Commentary 343, 350
(2003).
   Over the next century, this Court entered the fray of
judicial disqualifications only a handful of times. Drawing
from longstanding historical practice, the Court an-
nounced that the Due Process Clause compels judges to
disqualify in the narrow circumstances described below.
But time and again, the Court cautioned that “[a]ll ques-
tions of judicial qualification may not involve constitu-
tional validity.” Tumey, 273 U. S., at 523. And “matters of
kinship, personal bias, state policy, remoteness of interest
would seem generally to be matters merely of legisla-
tive discretion.” Ibid.; see also Aetna Life Ins. Co. v.
Lavoie, 475 U. S. 813, 828 (1986) (“The Due Process
Clause demarks only the outer boundaries of judicial
disqualifications”).
   First, in Tumey, the Court held that due process would
not tolerate an adjudicator who would profit from the case
if he convicted the defendant. The Court’s holding paral-
leled the common-law rule: “[I]t certainly violates the
Fourteenth 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 reach-
ing a conclusion against him in his case.” 273 U. S., at 523
(emphasis added); see also Ward v. Monroeville, 409 U. S.
57, 59, 61 (1972) (deciding that a mayor could not adjudi-
cate traffic violations if revenue from convictions consti-
tuted a substantial portion of the municipality’s revenue).
Later, applying Tumey’s rule in Aetna Life Ins., the Court
held that a judge who decided a case involving an insur-
ance company had a “direct, personal, substantial, and
pecuniary” interest because he had brought a similar case
against an insurer and his opinion for the court “had the
                     Cite as: 579 U. S. ____ (2016)                  11

                        THOMAS, J., dissenting

clear and immediate effect of enhancing both the legal
status and the settlement value of his own case.” 475
U. S., at 824 (alterations and internal quotation marks
omitted).
    Second, in In re Murchison, 349 U. S. 133 (1955), the
Court adopted a constitutional rule resembling the histori-
cal practice for disqualification of former counsel. Id., at
139. There, state law empowered a trial judge to sit as a
“ ‘one man judge-grand jury,’ ” meaning that he could
“compel witnesses to appear before him in secret to testify
about suspected crimes.” Id., at 133. During those secret
proceedings, the trial judge suspected that one of the
witnesses, Lee Roy Murchison, had committed perjury,
and he charged another, John White, with contempt after
he refused to answer the judge’s questions without counsel
present. See id., at 134–135. The judge then tried both
men in open court and convicted and sentenced them
based, in part, on his interrogation of them in the secret
proceedings. See id., at 135, 138–139. The defendants
appealed, arguing that the “trial before the judge who was
at the same time the complainant, indicter and prosecutor,
constituted a denial of fair and impartial trial required by”
due process. Id., at 135. This Court agreed: “It would be
very strange if our system of law permitted a judge to act
as a grand jury and then try the very persons accused as a
result of his investigations.” Id., at 137. Broadly speak-
ing, Murchison’s rule constitutionalizes the early Ameri-
can statutes requiring disqualification when a single
person acts as both counsel and judge in a single civil or
criminal proceeding.3
——————
  3 The Court has applied Murchison in later cases involving contempt

proceedings in which a litigant’s contemptuous conduct is so egregious
that the judge “become[s] so ‘personally embroiled’ ” in the controversy
that it is as if the judge is a party himself. Mayberry v. Pennsylvania,
400 U. S. 455, 465 (1971); see also Taylor v. Hayes, 418 U. S. 488, 501–
503 (1974).
12              WILLIAMS v. PENNSYLVANIA

                    THOMAS, J., dissenting

  Both Tumey and Murchison arguably reflect historical
understandings of judicial disqualification. Traditionally,
judges disqualified themselves when they had a direct and
substantial pecuniary interest or when they served as
counsel in the same case.
                              B
   Those same historical understandings of judicial dis-
qualification resolve Williams’ case. Castille did not serve
as both prosecutor and judge in the case before us. Even
assuming Castille’s supervisory role as district attorney
was tantamount to serving as “counsel” in Williams’ crim-
inal case, that case ended nearly five years before Castille
joined the Supreme Court of Pennsylvania. Castille then
participated in a separate proceeding by reviewing Wil-
liams’ petition for postconviction relief.
   As discussed above, see Part I–B, supra, this postconvic-
tion proceeding is not an extension of Williams’ criminal
case but is instead a new civil proceeding. See Finley, 481
U. S., at 556–557. Our case law bears out the many dis-
tinctions between the two proceedings. In his criminal
case, Williams was presumed innocent, Coffin v. United
States, 156 U. S. 432, 453 (1895), and the Constitution
guaranteed him counsel, Gideon v. Wainwright, 372 U. S.
335, 344–345 (1963); Powell v. Alabama, 287 U. S. 45, 68–
69 (1932), a public trial by a jury of his peers, Duncan v.
Louisiana, 391 U. S. 145, 149 (1968), and empowered him
to confront the witnesses against him, Crawford v. Wash­
ington, 541 U. S. 36, 68 (2004), as well as all the other
requirements of a criminal proceeding. But in postconvic-
tion proceedings, “the presumption of innocence [has]
disappear[ed].” Herrera v. Collins, 506 U. S. 390, 399
(1993). The postconviction petitioner has no constitutional
right to counsel. Finley, supra, at 555–557; see also John­
son v. Avery, 393 U. S. 483, 488 (1969). Nor has this Court
ever held that he has a right to demand that his postcon-
                 Cite as: 579 U. S. ____ (2016)           13

                    THOMAS, J., dissenting

viction court consider a freestanding claim of actual inno-
cence, Herrera, supra, at 417–419, or to demand the State
to turn over exculpatory evidence, Osborne, 557 U. S., at
68–70; see also Wright v. West, 505 U. S. 277, 293 (1992)
(plurality opinion) (cataloguing differences between direct
and collateral review and concluding that “[t]hese differ-
ences simply reflect the fact that habeas review entails
significant costs” (internal quotation marks omitted)).
And, under the Court’s precedents, his due process rights
are “not parallel to a trial right, but rather must be ana-
lyzed in light of the fact that he has already been found
guilty at a fair trial, and has only a limited interest in
postconviction relief.” Osborne, supra, at 69.
   Because Castille did not act as both counsel and judge in
the same case, Castille’s participation in the postconvic-
tion proceedings did not violate the Due Process Clause.
Castille might have been “personal[ly] involve[d] in a
critical trial decision,” ante, at 9, but that “trial” was
Williams’ criminal trial, not the postconviction proceed-
ings before us now. Perhaps Castille’s participation in
Williams’ postconviction proceeding was unwise, but it
was within the bounds of historical practice. That should
end this case, for it “is not for Members of this Court to
decide from time to time whether a process approved by
the legal traditions of our people is ‘due’ process.” Pacific
Mut. Life Ins. Co. v. Haslip, 499 U. S. 1, 28 (1991) (Scalia,
J., concurring in judgment).
                             C
   Today’s holding departs both from common-law practice
and this Court’s prior precedents by ignoring the critical
distinction between criminal and postconviction proceed-
ings. Chief Justice Castille had no “direct, personal, sub-
stantial pecuniary interest” in the adjudication of Wil-
liams’ fourth postconviction petition. Tumey, 273 U. S., at
523. And although the majority invokes Murchison, ante,
14              WILLIAMS v. PENNSYLVANIA

                    THOMAS, J., dissenting

at 6–8, it wrongly relies on that decision too. In Murchi­
son, the judge acted as both the accuser and judge in the
same proceeding. 349 U. S., at 137–139. But here, Cas-
tille did not. See Part II–B, supra.
   The perceived bias that the majority fears is instead
outside the bounds of the historical expectations of judicial
recusal. Perceived bias (without more) was not recognized
as a constitutionally compelled ground for disqualification
until the Court’s recent decision in Caperton v. A. T. Mas­
sey Coal Co., 556 U. S. 868 (2009). In Caperton, the Court
decided that due process demanded disqualification when
“extreme facts” proved “the probability of actual bias.” Id.,
at 886–887. Caperton, of course, elicited more questions
than answers. Id., at 893–898 (ROBERTS, C. J., dissent-
ing). And its conclusion that bias alone could be grounds
for disqualification as a constitutional matter “represents
a complete departure from common law principles.” Frank
618–619; see Blackstone 361 (“[T]he law will not suppose a
possibility of bias or favor in a judge”).
   The Court, therefore, should not so readily extend
Caperton’s “probability of actual bias” rule to state post-
conviction proceedings. This Court’s precedents demand
far less “process” in postconviction proceedings than in a
criminal prosecution. See Osborne, supra, at 69; see also
Cafeteria & Restaurant Workers v. McElroy, 367 U. S. 886,
895 (1961) (concluding that the Due Process Clause does
not demand “inflexible procedures universally applicable
to every imaginable situation”). If a state habeas petitioner
is not entitled to counsel as a constitutional matter in
state postconviction proceedings, Finley, supra, at 555–
557, it is not unreasonable to think that he is likewise not
entitled to demand, as a constitutional matter, that a state
postconviction court consider his case anew because a
judge, who had no direct and substantial pecuniary inter-
est and had not served as counsel in this case, failed to
recuse himself.
                 Cite as: 579 U. S. ____ (2016)          15

                    THOMAS, J., dissenting

  The bias that the majority fears is a problem for the
state legislature to resolve, not the Federal Constitution.
See, e.g., Aetna Life Ins., 475 U. S., at 821 (“We need not
decide whether allegations of bias or prejudice by a judge
of the type we have here would ever be sufficient under
the Due Process Clause to force recusal”). And, indeed, it
appears that Pennsylvania has set its own standard by
requiring a judge to disqualify if he “served in governmen-
tal employment, and in such capacity participated person-
ally and substantially as a lawyer or public official con-
cerning the proceeding” in its Code of Judicial Conduct.
See Pa. Code of Judicial Conduct Rule 2.11(A)(6)(b) (West
2016). Officials in Pennsylvania are fully capable of decid-
ing when their judges have “participated personally and
substantially” in a manner that would require disqualifi-
cation without this Court’s intervention. Due process
requires no more, especially in state postconviction review
where the States “ha[ve] more flexibility in deciding what
procedures are needed.” Osborne, supra, at 69.
                            III
   Even if I were to assume that an error occurred in Wil-
liams’ state postconviction proceedings, the question re-
mains whether there is anything left for the Pennsylvania
courts to remedy. There is not.
   The majority remands the case to “[a]llo[w] an appellate
panel to reconsider a case without the participation of the
interested member,” which it declares “will permit judges
to probe lines of analysis or engage in discussions they
may have felt constrained to avoid in their first delibera-
tions.” Ante, at 14. The majority neglects to mention that
the Supreme Court of Pennsylvania might have done just
that. It entertained Williams’ motion for reargument
without Castille, who had retired months before the court
denied the motion. The Supreme Court of Pennsylvania is
free to decide on remand that it cured any alleged depriva-
16              WILLIAMS v. PENNSYLVANIA

                    THOMAS, J., dissenting

tion of due process in Williams’ postconviction proceeding
by considering his motion for reargument without Cas-
tille’s participation.
                       *     *     *
   This is not a case about the “ ‘accused.’ ” Ante, at 14
(quoting Tumey, supra, at 532). It is a case about the due
process rights of the already convicted. Whatever those
rights might be, they do not include policing alleged viola-
tions of state codes of judicial ethics in postconviction
proceedings. The Due Process Clause does not require any
and all conceivable procedural protections that Members
of this Court think “Western liberal democratic govern-
ment ought to guarantee to its citizens.” Monaghan, Our
Perfect Constitution, 56 N. Y. U. L. Rev. 353, 358 (1981)
(emphasis deleted). I respectfully dissent.
