Courtesy Pennsylvania Department of Corrections In this undated photo, Terrance Williams is pictured. Williams is on death row for fatally beating Amos Norwood in 1984 in Philadelphia.

Updated at 6:30 p.m. ET: A Pennsylvania man on death row for the murder of his alleged sexual abuser failed to win clemency Monday from the state Board of Pardons.

Terrance "Terry" Williams, 46, is scheduled to be executed on Oct. 3. He is on death row at the State Correctional Institute at Greene in Pennsylvania for killing 56-year-old Amos Norwood with a tire iron in Philadelphia in 1984. Williams was 18 years old at the time of the murder. Defense lawyer Victor J. Abreu has said Williams' crimes were mitigated by the sexual abuse he experienced in his childhood. Norwood was allegedly one of his attackers.

After Monday’s hearing, the five-member board of pardons voted 3-2 in favor of clemency, The Philadelphia Inquirer reported. However, under state law, a unanimous vote was needed in order to provide a nonbinding recommendation to Pennsylvania Gov. Tom Corbett to change the lethal injection to life in prison without parole, the Inquirer reported.

The clemency hearing was granted after a petition filed on Sept. 6 called upon Corbett and the Pennsylvania Board of Pardons to stop the execution. The petition included a statement from Norwood's widow, who said, "Several years ago, after much prayer and self-reflection, I found the strength and courage to forgive Terry Williams."

Courtesy Germantown High School Williams is pictured here at age 17. His defense lawyers say his crimes are mitigated by a childhood of sexual abuse.

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"I do not wish to see Terry Williams executed,” she said in the statement.

On Friday, a Philadelphia judge agreed to hear testimony on the defense's claim that the prosecutor at Williams' 1986 trial withheld evidence from the jury pertaining to the sexual abuse, the Inquirer also reported.

One of Williams' attorneys, Shawn Nolan, said in a statement Monday that they are "deeply disappointed" in the denial for clemency. Nolan added that they will present new evidence on Thursday in court that reveals what the defense says is Williams' motive for the murders: years of sexual abuse.

"We are confident that a thorough review of the facts will make it clear that the jurors in this case did not have accurate and complete information about the crime or Terry Williams," Nolan said.

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Williams is also serving a life term for killing 50-year-old Herbert Hamilton when he was 17. Hamilton is another alleged abuser.

"[Williams] was a victim of horrific abuse since he was 6 years old,” Abreu told NBC News earlier this month. "The jury didn’t know that the two men who were killed were abusing him. That information was never presented to the jury."

Williams would be the first person executed in Pennsylvania in 13 years.

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