PHILADELPHIA—Prosecutors on Tuesday sought to win a death penalty appeal and have the state execute a man convicted of beating a church deacon to death in a cemetery when he was a teenager.

Inmate Terrance "Terry" Williams would be the first person executed in Pennsylvania in more than a decade. Williams, now 46, had killed another man five months earlier and claims both men were sexually abusing him.

For now, Williams has a stay of his scheduled execution. A state judge vacated his death sentence on Friday and ordered a new sentencing hearing after finding that prosecutors hid evidence at his 1986 trial.

But Philadelphia prosecutors appealed to the state's high court to overturn that ruling and reinstate the death penalty in time to execute Williams on Wednesday. Williams' death warrant expires at midnight, and prosecutors asked on Tuesday to respond to the objection filed by his lawyers.

The state Supreme Court could grant District Attorney Seth Williams' appeal, reject it or allow him to file another legal brief. Seth Williams is no relation to Terry Williams.

Prosecutors call Williams' abuse claim old news and say courts have rejected it.

"Defendant relies on a recycled, hindsight change of strategy, in which he now wants to have assassinated the character of the victim (who he testified at trial was a stranger to him)," they wrote in the appeal filed Friday.

However, a state judge had ruled earlier Friday that newly unearthed police and prosecution files support Williams' claims that authorities knew or suspected early on the two victims were sexually involved with teen boys. The jury in Williams' second murder trial, which condemned him to death, never heard that.

In another development, state Supreme Court Chief Justice Ronald Castille has refused defense requests that he step down from the case because he was the top prosecutor when Williams was tried. Castille filed notice on Monday, without comment, that he won't recuse himself.

Williams' lawyers accuse Castille of a clear conflict of interest. And they said he has shown antagonism toward the Federal Public Defenders Office in denying recusal motions in some of the 45 other death penalty cases he oversaw as Philadelphia's district attorney.

"As district attorney, he wrote a note approving that his staff seek the death penalty against Terry," said Shawn Nolan, assistant chief of the defenders' capital habeas unit. "We thought recusal was a reasonable request under these circumstances. Justice Castille disagreed."

Williams would be the first person executed in Pennsylvania in 50 years who had not abandoned his appeals. A flurry of activity is expected before the Wednesday deadline.

Besides the prosecution's pending appeal in state court, Williams' lawyers could file an 11th-hour plea to the U.S. Supreme Court, which last year rejected Williams' appeal.

A Philadelphia jury sentenced Williams to death in 1986 for fatally beating the 56-year-old church deacon, Amos Norwood. Jurors heard only that the motive was robbery. Williams and an accomplice were caught after using a credit card they'd taken from the victim.

However, the accomplice, Marc Draper, testified last week that he told police and the trial prosecutor that Norwood and Williams had a sexual relationship. He said they didn't want to hear it.

Williams also was convicted of killing a 50-year-old sports booster when he was 17. He was tried as an adult and convicted of murder. But that slaying was an aggravating factor that helped sway the Norwood jury toward a death sentence. Five jurors have joined Norwood's widow in signing petitions in recent years to spare his life. The jurors said they did not know about the abuse allegations or that in Pennsylvania a life sentence for first-degree murder means no parole.

There are about 200 people on Pennsylvania's death row. Only three people have been executed since the death penalty was restored in 1978.