NASHVILLE, Tenn. (AP) — Tennessee death row inmate Nicholas Sutton should be spared from execution because he transformed himself in prison from a killer to someone who saved the lives of prison employees and fellow inmates, his attorneys argue in a clemency petition.

Sutton was sentenced to death in 1985 for stabbing fellow inmate Carl Estep to death after a confrontation over a drug deal. Sutton, now 58, was 23 years old at the time and already serving a life sentence for killing his grandmother when he was 18 years old. He had also been convicted of murdering Charles Almon and John Large in North Carolina when he was 18.

The petition sent to Gov. Bill Lee on Tuesday, a little more than a month before Sutton’s scheduled execution date of Feb. 20, says that Sutton takes responsibility for these deaths and is “profoundly remorseful.” While the petition says Sutton makes no justification for the murders, his attorneys point out that he was raised by a violent, abusive and mentally ill father who introduced him to drugs at the age of 12.

Death row was the first stable environment Sutton had ever lived in, his attorneys argue, and it also allowed him to get off drugs for the first time in many years. Sobriety and stability allowed Sutton to better himself and transform his life, they argue.

“Nick Sutton has gone from a life-taker to a life-saver. Five Tennesseans, including three prison staff members, owe their lives to him,” the petition states.

Former Correction Lt. Tony Eden is quoted as saying that Sutton saved his life during a 1985 prison riot when Eden was surrounded by a group of armed inmates who tried to take him hostage.

“Nick and another inmate confronted them, physically removed me from the situation and escorted me” to safety, Eden says in the petition.

Cheryl Donaldson, a former manager of Tennessee’s death row unit, recalls in the petition that in 1994 she slipped and hit her head hard on the floor. Sutton “sprang into action, helped me to my feet, retrieved my keys and radio, and alerted staff to come to my assistance,” she says.

The petition also recounts the story of former Hamblen County Sheriff’s Deputy Howard Ferrell, now deceased, who said that in 1979 Sutton stopped another inmate from attacking him from behind as he was trying to break up a fight.

And the petition includes statements from the mother of Paul House, a fellow inmate who was released after many years on death row. House developed multiple sclerosis in prison but was denied a wheelchair or walker, so Sutton carried him around the prison, Joyce House says.

She credits Sutton’s care with saving her son’s life.

“As a mother, it was so difficult not to be able to care for my son. I owe so much to Nick for providing Paul with the care that I was unable to give him,” she says in the petition.

The petition also says inmate Pervis Payne credits Sutton’s quick action in calling for medical assistance with saving his life after he fell ill from a punctured intestinal tract.

In addition to stressing his rehabilitation, the petition makes several legal arguments for commuting Sutton’s sentence. They include the fact that Sutton was visibly shackled and handcuffed during his 1985 trial. Attorneys quote a U.S. Supreme Court decision that found shackling “undermines the presumption of innocence.”

Sutton’s current attorneys also fault his previous counsel for not presenting his history of childhood trauma and abuse as mitigating factors for the jury to consider. And they point out that Sutton was offered a life sentence by prosecutors, but only if a codefendant pleaded guilty and accepted a 30-40 year sentence. That codefendant was later acquitted by a jury.