George Ochoa, a 38-year-old death row inmate convicted of murdering an Oklahoma City couple during a home invasion in 1993, was executed by lethal injection Tuesday in Oklahoma’s sixth execution this year, despite his lawyers’ claims that he was mentally unfit to be put to death.

In a press release, Oklahoma Attorney General Scott Pruitt said, “Ochoa was convicted and sentenced to death for the first-degree murders of Francisco Morales, 38, and wife, Maria Yanez, 35. According to the report, Morales suffered 12 gunshot wounds and Yanez suffered 11 gunshot wounds while in their bedroom ... The victim’s children were in the home at the time of the murders.”

Ochoa was given a death sentence for the crime along with co-defendant Osvaldo Torres, 37, who later testified that the two had planned the burglary together. But in 2004, then-Gov. Brad Henry commuted Torres’ sentence to life in prison without the possibility of parole, in part due to Torres’ claim that he had not anticipated that Ochoa would murder the victims.

“I never killed anyone,” Torres said during the 2004 clemency hearing. “And I never knew George was going to kill anyone.”

Ochoa maintained to the end that he was wrongfully convicted. In the death chamber, Ochoa was asked by a prison warden if he had any final words, but said only, “I’m innocent.”

According to McAlester News Capital, the blinds separating Oklahoma State Penitentiary’s death chamber from the witness room were raised at 6:01 pm, allowing 12 of the victims’ relatives full view of Ochoa’s execution; 19 relatives had actually arrived that day, but the prison permitted space for only 12. One minute later, Deputy Warden Art Lightle announced that the execution would begin.

Ochoa was injected with a combination of sodium thiopental, vecuronium bromide and potassium chloride, the standard three-drug cocktail currently employed in all Oklahoma executions. He reportedly blinked rapidly, and briefly chewed on his lower lip before leaning his head back on the gurney and closing his eyes. Within five minutes the color had drained from his face; his time of death was reported at 6:07 p.m. CST. None of Ochoa’s relatives were present, although five were scheduled to attend.

In August, Oklahoma put to death Michael Hooper, marking their 100th execution since the reinstating of the death penalty. One month before his execution Hooper demanded that the state  have an additional dose of pentobarbital on hand as a precautionary measure if the drug proved ineffective at sedating him. His attorney, Jim Drummond, argued that in the event that the sedative did not work, the latter drugs could cause him pain, a violation of the Eighth Amendment.