FILE - This June 29, 2011 file photo provided by the Oklahoma Department of Corrections, shows Clayton Lockett. A report on a problematic execution in Oklahoma shows lethal drugs caused the inmate to die, not a heart attack, after the state�s prisons chief halted efforts to kill him. (AP Photo/Oklahoma Department of Corrections, File)
OKLAHOMA CITY (AP) -- An Oklahoma death row inmate who died following a problematic execution succumbed to the lethal drugs he was administered, not a heart attack, after the state's prisons chief halted efforts to kill him, an autopsy report released Thursday says.
Department of Corrections Director Robert Patton had said inmate Clayton Lockett died from a heart attack several minutes after he ordered the execution stopped. But the autopsy report performed for the Oklahoma Department of Public Safety says all three execution drugs were found throughout Lockett's system. A medical examiner declared that the cause of death was "judicial execution by lethal injection."
Oklahoma put executions on hold after Lockett gasped and writhed against his restraints for several minutes after his April execution began. Lockett was poked several times as medical technicians tried to find a vein before settling in using one at his groin.
Gov. Mary Fallin has ordered public safety officials to review the events surrounding Lockett's death, including state execution protocols that had been changed in the weeks before Lockett's execution. The state Court of Criminal Appeals agreed to not schedule executions for six months. Three are set for mid-November and early December.
A spokesman for Fallin, Alex Weintz, said the autopsy report will be part of the DPS review.
"We suspect they are in the final stages of that process," Weintz said.
He said Fallin still supports use of the death penalty despite the problems encountered with Lockett's execution.
"But we want our executions to be successful," Weintz said. "She has asked DPS to make recommendations on what possible updates to the protocols we can pursue."
The autopsy report details Lockett's cause of death and does not include recommendations about the state's execution protocols.
Under the protocols, Oklahoma used the sedative midazolam for the first time. The drug was also used in lengthy attempts to execute an Ohio inmate in January and an Arizona prisoner last month. Each time, witnesses said the inmates appeared to gasp for air moments after their executions began and continued to labor for air before being pronounced dead.
Patton, the director of the Oklahoma Department of Corrections, called for a complete "review/revision" to the execution protocols in Oklahoma following the Lockett execution, and said he was willing to adopt other states' protocols to "ensure the Oklahoma protocol adopts proven standards."
Among his concerns were that the state's current protocol puts all the responsibility and decision-making in the hands of the Oklahoma State Penitentiary warden, who is responsible for overseeing executions. Patton, who came to Oklahoma from the Arizona Department of Corrections, didn't specifically mention the drug midazolam or any other formula approved for use in the Oklahoma death chamber.
Midazolam is part of a three-drug and a two-drug protocol in Oklahoma. Lockett's execution used a three-drug protocol -midazolam, vecuronium bromide and potassium chloride. The state also has a protocol that would use midazolam with hydromorphone, the same combination used in the problematic executions in Ohio and Arizona this year.