COLUMBIA, S.C. - An inmate scheduled to die Friday by lethal injection for killing an Aiken County convenience store clerk is asking the governor to spare his life.

Lawyers for Jerry McWee want Gov. Mark Sanford to commute McWee's death sentence to life without parole because they say his co-defendant struck a plea bargain that may have kept him from the death chamber.

McWee, 51, also has been a model prisoner during his 10 years on death row, only committing one minor infraction of having more than $25 in an account inmates use to buy personal items, according to the clemency petition filed Monday.

But McWee faces an uphill fight. No South Carolina governor has reduced a death sentence to life in prison since the death penalty was reinstated nearly 30 years ago. McWee will be the 30th inmate sent to the death chamber during that time.

Sanford has already refused one clemency petition since taking office, allowing David Clayton Hill to be put to death on March 19. His spokesman, Will Folks, said he isn't sure if the governor is aware that none of his predecessors have spared an inmate's life.

"I don't think he looks at what other people have done or what the statistics are," Folks said. "I think he looks at each individual case and makes a decision based on its merit."

McWee's only other hope is a case before the U.S. Supreme Court, saying the jury in his trial should have known he would have been 71 years old before he became eligible for parole. The state Supreme Court has already denied a similar appeal last month on a 3-2 vote.

If McWee's sentence was changed to life in prison now, he could never be paroled under current law, his lawyer John Hardaway said.

In the clemency petition, McWee's lawyers agree he is the one who fired the gun that killed Aiken County convenience store clerk John Perry in July 1991. Authorities said McWee took Perry to the back of the store and shot him twice in the head before stealing $350 from the cash register.

But they said McWee was a down-on-his-luck former police officer and paramedic who had never been in trouble before until he met George Scott while working as a security guard at Waffle House.

The two became roommates and Scott needed money because he was using drugs, Hardaway wrote in the petition.

McWee killed the clerk because "he was nervous and scared by the situation, and because Scott had threatened him," Hardaway wrote.

A week later, McWee and Scott went to their boss' house and shot and killed him. This time Scott pulled the trigger. The gun used in both killings was found in McWee's trunk after McWee called 911 to report the death.

Scott immediately began talking to investigators and testified against McWee at his trial. He told jurors he had received no deal, but several years later said he did not reveal his deal because it wasn't in writing, Hardaway wrote.

Also one of the chief investigators in the cases was the father of McWee's estranged wife, making him much more likely to encourage a deal with Scott, according to the petition.

Both men pleaded guilty to the second killing and received life sentences.

The McWee case in 1994 was the first death penalty trial for prosecutor Barbara Morgan, who said she has no doubts McWee should die for what he did.

"It's what it calls for," said Morgan, who during her closing arguments in the trial said McWee was "like a dog turned wrong and gone rabid."

Morgan disputes several items in the clemency petition, including defense lawyers pointing out McWee called 911. She said the call wasn't right after the shooting.

"They go to Hardee's and eat," Morgan said. "Then they come back and report it as if they found him murdered."

McWee was the ringleader in the killings and used his emergency medical training to take the pulse of the second victim after he was shot, Morgan said. When he detected a heartbeat, he had Scott shoot him again and showed him where to fire the shot, she said.

The 10-year wait for justice has been hard on Perry's family and each time McWee tries to avoid the death chamber brings the hurt back, Morgan said.

"The wound keeps getting salt in it all of the time," she said.