Oklahoma revealed Tuesday it intends to use an untested cocktail to execute two death-row inmates later this month.
A letter from the state's Attorney General said that the Oklahoma Department of Corrections will utilize three drugs -- midazolam, pancuronium bromide and potassium-chloride -- to kill convicted murderers Clayton Lockett and Charles Warner.
The state came up with the new protocol after revealing in court papers last month that it had not been able to find two of the drugs for its old protocol: pentobarbital and vecuronium bromide.
The Oklahoma Court of Criminal Appeals rescheduled Lockett's execution for April 22 and Warner's for April 29 after learning the state didn't have the drugs and planned to come up with a new method.
Lawyers for Lockett and Warner say the new cocktail is essentially untested because it uses a smaller dosage of midazolam than is used in Florida, which has a similar protocol.
"This created a serious and substantial risk that the condemned prisoner will not be adequately anesthetized before he is injected" with the other two drugs, the lawyers said in a statement.
The pancuronium bromide, a paralytic, and the heart-stopping potassium chloride would cause "excruciating pain," if the midazolam didn't do its job -- in violation of the constitutional protection against cruel and unusual punishment, they said.
Midazolam is one of the drugs used in the execution of Ohio prisoner Dennis McGuire, whose death took 25 minutes and who gasped for breath, according to witnesses.
Lockett and Warner also want to force Oklahoma to disclose which pharmacy supplied the drugs.
Death penalty states are anxious to keep that information anonymous to protect compounding pharmacies from bad publicity and legal hassles.
Prison systems have been forced to use compounding pharmacies because the manufacturers of several drugs have used to sell them for executions.