As the city's top prosecutor, Castille approved the decision to seek the death penalty and to defend the sentence on appeal.
Now, as chief justice of the state's high court considering whether to reinstate Williams' execution Wednesday, Castille's history seems a conflict of interest, the defense argues.
In 18 years on the court, Castille has rebuffed recusal motions based on his tenure as district attorney from 1986 to 1991.
Frequently, those motions have been filed in capital cases by the Federal Defender's death-penalty unit, including Williams' current lawyers Shawn Nolan and Billy Nolas.
In a 2006 death-penalty opinion in a Philadelphia capital case, Commonwealth v. Rainey, Castille wrote that as the prosecutor, he signed thousands of documents in cases where he had no active role.
Castille wrote that court rules did not require recusal of Supreme Court justices, because of the "special considerations implicated when a Judge or Justice on a jurisdiction's highest court is asked to recuse."
Unlike the lower courts, Castille wrote, there is no way to swap in a judge on the Supreme Court: "There is no higher court of appeal that may review an equally divided decision of this Court and thereby establish the law for our jurisdiction."
The state's seven-member high court is already one justice short because of corruption charges facing Justice Jane Orie Melvin, who has been suspended.
The Philadelphia District Attorney's Office had no comment on the latest defense filing.
Monday's defense motions responded to the district attorney's plea asking the court to set aside Friday's ruling by Common Pleas Court Judge M. Teresa Sarmina, who stayed Wednesday's execution of Williams, 46.
The death warrant for Williams expires at midnight Wednesday. If the stay is later reversed, Gov. Corbett would have to sign a new death warrant.
After two days of hearings, Sarmina ruled that the integrity of Williams' death sentence had been undermined by evidence that the prosecutor and police withheld from Williams' lawyer evidence of Norwood's sexual abuse of teenage boys.
Williams, then an 18-year-old Cheyney University freshman and football star from Germantown High School, was sentenced to death for the June 11, 1984, murder of Norwood, 56, a Germantown church volunteer, whose body was found in a cemetery, head bludgeoned with a tire iron, and then set afire.
Prosecutors alleged that Williams and admitted accomplice Marc Draper, also 18, killed Norwood during a robbery and that Williams did take Norwood's car, cash, and credit cards to Atlantic City.
At trial, Williams testified that he did not know Norwood and was not there when he was killed.
In staying the execution, Sarmina said she believed Draper's recantation statement that authorities ignored his first account of Norwood's killing: in a rage fueled by Williams' five years of sexual abuse by Norwood and others.
Had prosecutors given that information to the defense attorney before trial, Sarmina said, the jury might have spared Williams' life and sentence him to life in prison without parole.
Contact Joseph A. Slobodzian
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