"I offer my sorrow and my heart goes out to y'all," he told relatives of the murder victims as they watched through a death chamber window. "I know you believe that you're going to have closure tonight. As I stand before God today, the true judge, I had nothing to do with the death of your family."
Kelly was condemned for fatally shooting 22-month-old Devin Morgan in a May 1984 spree that also took the lives of his parents, Jerry and Brenda Morgan. Their bodies were found at their home in Gregg County, northwest of Longview and about 100 miles east of Dallas.
Kelly, the former owner of a Tyler truck repair shop, became the 10th Texas prisoner executed this year and the first of a dozen scheduled to die over the next six weeks. Another execution is set for Thursday evening.
His lethal injection was carried out about two hours after the U.S. Supreme Court refused to stop it, denying a last-day appeal.
Kelly said in an interview last week that he didn't want a reprieve and was looking forward to "go home to God."
"I have friends and family who are sad, but I am happy," he said. "I'm not going to die. I have eternal life."
Kelly already was serving a 30-year prison term for murder when he was convicted of the child's death and sent to death row.
From the death chamber, he acknowledged the other slaying.
"I ask for forgiveness because I do stand guilty for my involvement for that," he said just before singing a song praising God. He was still singing as the lethal drugs took effect.
Twelve minutes later, he was pronounced dead.
The Morgan murders went unsolved for six years until a man in Michigan told authorities that his former wife, who also had been married to Kelly, had information about the case.
Prosecutors said his ex-wife never felt she could come forward because she feared Kelly, who turned to drug dealing and manufacturing after his truck repair business failed because of his drug addiction.
By then, Kelly said he had found religion in the Gregg County Jail, where he was being held on a drug charge and then was implicated in the aggravated sexual assault of two fellow inmates. He said he turned down several plea deals in the triple slaying case, saying that accepting the offers would force him to lie.
"If I was guilty, I would plead guilty," he said from death row. "But I can't stand before God on a lie."
Relatives of the slain family declined to speak with reporters in Huntsville Tuesday evening.
Lori Kubecka, who was 10 when her aunt, uncle and nephew were killed and was among the people watching Kelly die, told the Longview News-Journal before the execution that the shootings left her traumatized.
"To this day, I still cannot stay by myself overnight," she said. "Even though he's behind bars, you still have this thought in the back of your mind that if this man could do it, anyone could come into my home and kill my family."
At Kelly's trial, prosecutors told jurors Jerry and Brenda Morgan had been city marshal reserve officers and they believed Kelly thought they were providing information about him to authorities.
Scheduled to die on Thursday is Kevin Watts, 27, convicted of the execution-style shootings of three people during a robbery at a San Antonio restaurant in 2002.
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