(Reuters) - Oklahoma inmate Clayton Lockett died during a botched execution on Tuesday, minutes after a doctor had called a halt to the procedure, raising more questions about new death penalty cocktails used by the state and others.
Thirteen minutes after a doctor administered a lethal injection at the state's death chamber in McAlester, Lockett lifted his head and started mumbling. The doctor halted the execution, said state corrections department spokesman Jerry Massie.
Lockett died of an apparent massive heart attack about 40 minutes after the procedure started, he said.
"We believe that a vein was blown and the drugs weren't working as they were designed to. The director ordered a halt to the execution," Massie said.
The troubled execution was expected to have national implications, with lawyers for death row inmates having argued that new lethal injection cocktails used in Oklahoma and other states could cause undue suffering and violate constitutional protections against cruel and unusual punishment.
"This could be a real turning point in the whole debate as people get disgusted by this sort of thing," said Richard Dieter, the executive director of the Death Penalty Information Center, which monitors capital punishment.
"This might lead to a halt in executions until states can prove they can do it without problems. Someone was killed tonight by incompetence," Dieter said.
Witness Ziva Branstetter told broadcaster MSNBC Lockett was thrashing about and appeared to be in pain. The state blocked off the scene from witnesses a few minutes after the troubles started by drawing a curtain on the execution chamber.
"His body was sort of bucking. He was clenching his jaw. Several times he mumbled phrases that were largely unintelligible," she said.
The execution had been put on hold for several weeks due to a legal fight over a new cocktail of chemicals for the lethal injection, with lawyers arguing the state was withholding crucial information about the drugs to be used.
'TORTURED TO DEATH'
Last week, the state Oklahoma Supreme Court lifted stays of execution for Lockett and another inmate who was also scheduled to be executed on Tuesday, saying the state had provided them with enough information about the lethal injection cocktail to meet constitutional requirements.
The other inmate, Charles Warner, who was scheduled to be put to death two hours after Lockett on Tuesday, has been granted a 14-day stay of execution after the problems.
"I have asked the Department of Corrections to conduct a full review of Oklahoma's execution procedures to determine what happened and why during this evening's execution of Clayton Derrell Lockett," Governor Mary Fallin said.
Oklahoma had set up a new lethal injection procedure and cocktail of chemicals earlier this year after it was no longer able to obtain the drugs it had once used for executions.
"After weeks of Oklahoma refusing to disclose basic information about the drugs for tonight's lethal injection procedures, tonight Clayton Lockett was tortured to death," said Madeline Cohen, an attorney for Warner.
Oklahoma and other states have been scrambling to find new suppliers and chemical combinations after drug makers, mostly in Europe, imposed sales bans because they objected to having medications made for other purposes being used in lethal injections.
Attorneys for death row inmates have argued that the drugs used in Oklahoma and other states could cause unnecessarily painful deaths, which would amount to cruel and unusual punishment in violation of the U.S. Constitution.
Oklahoma uses three drugs in its new lethal injection mixture, which consists of midazolam to cause unconsciousness, vecuronium bromide to stop respiration and potassium chloride to stop the heart, the Department of Corrections said.
In order to obtain drugs used for execution, Oklahoma and other states have turned to compounding pharmacies, which are lightly regulated agencies that combine chemicals for medical purposes.
Lawyers for death row inmates have argued there may be problems with purity and potency of the chemicals that come from these compounding pharmacies, raising questions about whether they should be used to prepare lethal injection drugs.
Lockett, 38, was convicted of first-degree murder, rape, kidnapping and robbery for a 1999 crime spree with two co-defendants. He was found to have shot teen-ager Stephanie Nieman and buried her alive in a shallow grave where she eventually died.
Warner, 46, was convicted for the 1997 first-degree rape and murder of 11-month-old Adrianna Waller, who was the daughter of his then-girlfriend, Shonda Waller.
Lockett and Warner had been scheduled to be executed in March but had their death sentences put on hold after lower courts ruled that the state needed to provide more information about the drugs that would be used to execute them and the supplier of the pharmaceuticals.