John David Duty, 58, apologized to the family of Curtis Wise and thanked his own family before lethal drugs were injected at the state prison in McAlester, the Tulsa World reported. He repeated "Thank you, Lord" several times as he began to lose consciousness.
The state Department of Corrections put Duty to death with a new combination of drugs. The department ran out of sodium thiopental this year and substituted pentobarbital, normally used for animal euthanasia, to knock Duty out followed by vecuronium bromide and potassium chloride.
The combination apparently caused no problems, the newspaper said.
Duty was serving multiple life sentences for rape, robbery and assault with intent to kill in 1978 when he strangled Wise. Wise's family did not witness his execution.
"To the family of Curtis Wise, I'd like to make my apology. I hope one day you'll be able to forgive me, not for my sake but for your own," Duty said. "My family and friends are here too. Thank you. You've all been a blessing. Thank you Lord Jesus. I'm ready to go home."