WASHINGTON - A US death row inmate writhed in agony and mumbled incoherently in a botched execution using untested drugs, before dying Tuesday of a heart attack 40 minutes into the ordeal, news reports said.
The gruesome end to the life of Clayton Lockett, a convicted murderer and rapist, prompted allegations that what he underwent amounted to torture. It also caused the state of Oklahoma, where Lockett died, to postpone the scheduled execution of a second inmate.
Lockett was administered a new, untested three-drug protocol in what would have been the central state's first double execution in 80 years.
But Oklahoma Department of Corrections Director Robert Patton ordered the execution of Lockett stopped about three or four minutes after the start of the injection at 6:23 pm (2323 GMT), citing a "vein failure," a prisons spokesman said.
Lockett died of a massive heart attack at 7:06 pm after receiving all three drugs, spokesman Jerry Massie said.
Even though he was administered the injection, "the drugs didn't go into the system," the spokesman said.
The drugs were a sedative, an anesthetic and a lethal dose of potassium chloride.
Patton immediately ordered a 14-day delay for the execution of Charles Warner, who had been set to be executed two hours after Lockett.
"About 13 minutes into the execution, after he had been declared unconscious, the inmate began writhing in pain. His body was sort of bucking. He was clenching his jaw," Tulsa World editor Ziva Branstetter told MSNBC television.
"Several times he mumbled phrases that were unintelligible. Only word we could make out was: 'Man!' He seemed to be in a lot of pain.
"Several times he rose, his head and shoulders rose up off the gurney as if he was trying to get off the gurney." Shortly thereafter, the prison warden closed the blinds, preventing reporters from witnessing what was going on in the execution chamber, Branstetter said.