By Heide Brandes
OKLAHOMA CITY (Reuters) - Oklahoma is set to put to death two men convicted of murder and rape in unrelated cases in a double execution on Tuesday after ending a several weeks' long legal fight over the secrecy concerning the state's lethal injection procedure.
Clayton Lockett and Charles Warner will be put to death after Oklahoma's Supreme Court lifted their stays last week, saying the state had provided them with enough information about the lethal injection cocktail to meet constitutional requirements.
The executions are planned for 6 and 8 p.m. CDT at the state's death chamber in McAlester. Lockett will be executed first.
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 burying 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 on the drugs that would be used to execute them and the supplier of the pharmaceuticals.
The crimes for which they were convicted were not related, but their executions became linked in a lawsuit about the lethal injection drugs.
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.
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.
The Oklahoma Supreme Court lifted a stay of execution last week.
The court said their records indicate that the inmates have been provided with the identity and dosages of the drugs for the lethal injections and there were no pending secrecy concerns that would merit a further stay.
(Writing by Jon Herskovitz; Editing by Sharon Bernstein and Cynthia Osterman)