Georgia authorities on Tuesday prepared to execute the state’s longest-serving death row inmate for the murder of his wife.

Jack Alderman, 57, who has been on death row for 33 years, is scheduled to be executed by lethal injection at 7 p.m. at the Georgia Diagnostic and Classification Prison in Jackson.About 6 p.m. Tuesday, Alderman’s lawyer, Michael Seiml, said the U.S. Supreme Court had rejected Alderman’s last appeal. The Georgia Supreme Court on Tuesday afternoon had yet to act on his request for a stay.

Alderman was sentenced to die for killing his wife, Barbara, in 1974.

He and an accomplice beat her with a crescent wrench, choked her and left her submerged in water in a bathtub at their Chatham County home. The men then visited two Savannah bars before dumping her body in a creek near her family’s home in Rincon. Prosecutors said they wanted to collect $20,000 in life insurance money.

On Tuesday, the Georgia Board of Pardons and Paroles rejected Alderman’s bid for clemency for the second time. Alderman’s father was among those who asked the five-member panel to spare his life.

His supporters argue that Alderman has been a model prisoner and mentor in his more than three decades behind bars. They have also noted that his accomplice, John Arthur Brown, was paroled after just 12 years in prison.

“They were treated very differently,” Alderman’s lawyer Michael Siem said.

But David Lock, an assistant district attorney in Chatham County, said Alderman instigated the crime.

“He was more culpable, without him, the crime would not have taken place,” Lock said.

Alderman was just a day away from execution last October when Georgia’s top court issued a stay to give the U.S. Supreme Court time to act on a constitutional challenge to lethal injection. Earlier this year, the justices cleared the way for executions to resume when they ruled lethal injection does not amount to cruel and unusual punishment.

As the case has slowly wound its way through the lengthy appeals process, the delay has been agonizing for Barbara Alderman’s sister, Rheta Braddy. She said her mother has died while Alderman has been on death row and that her brother-in-law has waited long enough to pay for his crime.

“It is time for Barbara to have some justice,” Braddy said.