In 1986, Terrance Williams was convicted of murder and sentenced to death in Pennsylvania state court. At the time of Williams’s trial and sentencing, Ronald Castille was the elected district attorney of Philadelphia. In addition to heading the office that prosecuted Williams, Castille personally authorized pursuit of the death penalty in Williams’s case. Though Williams’s direct appeal and initial request for post-conviction relief were unsuccessful, a post-conviction court found in 2012 that relevant mitigating evidence in Williams’s case had been suppressed by the trial prosecutor. Based on these findings, the post-conviction court stayed Williams’s execution and granted him a new penalty hearing, an order that the state immediately appealed.

By the time of that appeal, district attorney Castille had been elected Chief Justice of the Pennsylvania Supreme Court, and Williams filed a motion requesting that Castille recuse himself or, at least, refer the motion to the full court for decision. Castille declined to do either, and instead joined the court’s opinion reversing the grant of relief. Castille also wrote a separate concurrence in which he excoriated both the attorneys who had helped Williams seek that relief and the post-conviction court for granting it. Williams sought to appeal the Pennsylvania Supreme Court’s ruling, filing a petition for writ of certiorari with the United States Supreme Court on June 12, 2015, which was granted on October 1, 2015.

On December 7, 2015, CAC filed a friend-of-the-court brief in support of Williams, which argued that the judicial conflict of interest in this case is so extreme and obvious that it clearly contravenes the Constitution’s fundamental commitment to impartial justice. As our brief explained, the commitment to an impartial justice system is central to the constitutional guarantee that all persons are entitled to “due process of law,” and the Supreme Court’s precedents confirm that the Due Process Clause requires impartial adjudicators. By virtue of his prior involvement in Williams’s prosecution, Chief Justice Castille’s participation in the case denied Williams the impartial adjudicators to which he was entitled.

Castille was the Philadelphia District Attorney and thus head of the office that prosecuted Williams throughout Williams’s trial, sentencing, and direct appeal. Indeed, Castille personally approved pursuit of the death penalty against Williams, and his name appeared on the appellate brief asking that Williams’s conviction be affirmed. Moreover, the issue Castille was asked to decide in this case was whether the trial prosecutor in Williams’s case—that is, an attorney on Castille’s staff and for whose conduct Castille was ultimately responsible—suppressed evidence in violation of the law, as the lower court found. An affirmance of the lower court’s order would necessarily impugn the integrity and reputation of the office Castille led and thus his own reputation as well. For a judge with that level of personal interest in a case to participate in deliberations, potentially influence his colleagues’ votes, and then vote on the case himself, creates not only the appearance of unfairness, but also the probability of it, both of which the Due Process Clause prohibits.

The Court heard oral argument on February 29, 2016. On June 9, 2016, the Court held, by a 5-3 vote, and as we had urged, that Chief Justice Castille’s denial of the recusal motion and his subsequent participation in Williams’s post-conviction appeal violated the Due Process Clause. In an opinion by Justice Kennedy, the Court explained that “there is an impermissible risk of actual bias when a judge earlier had significant, personal involvement as a prosecutor in a critical decision regarding the defendant’s case,” and it affirmed that “[b]oth the appearance and reality of impartial justice are necessary to the public legitimacy of judicial pronouncements and thus to the rule of law itself.” Chief Justice Roberts and Justices Alito and Thomas dissented.