Lawyers for a Georgia death row inmate scheduled to die this week are asking the state parole board to spare his life, saying he has turned his life around and is having a positive impact in prison.

Daniel Anthony Lucas is set to be put to death Wednesday at the state prison by injection of the barbiturate pentobarbital. The State Board of Pardons and Paroles, which is the only entity authorized to commute a death sentence, plans to hold a clemency hearing for him Tuesday.

Lucas, 37, received the death sentence in 1999 for the killings of Steven Moss, 37, his 11-year-old son Bryan and 15-year-old daughter Kristin, who interrupted a burglary at their home near Macon in central Georgia.

In a clemency petition filed with the parole board, Lucas' lawyers outline what they say was a troubled childhood plagued by drugs and violence. He was 19 at the time of the slayings and his own drug and alcohol use had spiraled out of control, his lawyers wrote.

"He was at rock bottom, lost and felt like his life was meaningless," the clemency petition says.

Lucas and another man, Brandon Rhode, broke into the Moss home in April 1998 looking for drugs, cash or things they could sell to get money for drugs, Lucas' lawyers wrote.

Bryan Moss saw them through a front window, and entered through a back door armed with a baseball bat, prosecutors have said. They say the two then wrestled Bryan to a chair and Lucas shot him in the shoulder.

Lucas then led the boy to a bedroom and shot him multiple times, prosecutors have said.

Rhodes met Kristin as she got home from school and forced her to sit on a chair and shot her twice with a pistol, according to court records. Rhode then ambushed Steven Moss when he arrived home, shooting him four times with the same pistol. Lucas later shot all three victims again to make sure they were dead.

Moss' wife, Gerri Ann, discovered the bodies when she returned home from work.

Lucas' mother had relationships with a string of abusive men, including his father, the clemency petition says. Lucas was "scared during much of his childhood" and turned to drugs, smoking marijuana and drinking by the time he was in seventh grade. Within a few years, he was using LSD, mushrooms and methamphetamine and, in eleventh grade, dropped out of school with his mother's approval.

"At 19, Daniel was a reckless and desperate alcoholic and addict, and he committed a horrible crime," his lawyers wrote. "But he is not pure evil, and he is not beyond redemption."

Lucas has expressed remorse for the harm he caused and has accepted responsibility for what he did, frequently thinking of Gerri Ann Moss and the pain he caused her, his lawyers wrote.

He has been in prison for about half his life and has been a model inmate, spending his time drawing and reading and serving as an inspiration to other inmates, the clemency petition says. He has become a Buddhist and spends part of his meditation practice acknowledging the suffering he caused and praying for the victims' relief, his lawyers wrote.

Rhode, who was also convicted for the killings, was executed in September 2010.

Lucas' death would bring the number of court-ordered executions in Georgia this year to five. That would tie a record, set in 1987 and matched last year, for the most executions carried out by the state in a calendar year since the death penalty was reinstated nationwide in 1976.