Clayton Lockett, 38, was scheduled to die by lethal injection for the 1999 shooting death of 19-year-old Stephanie Nieman. But corrections spokesman Jerry Massie said the stay order put the punishment at the Oklahoma State Penitentiary in McAlester on hold.
The order, issued Monday, also canceled the scheduled April 29 execution of inmate Charles Warner, 46, who was convicted in the 1997 death of his roommate's 11-month-old daughter.
The stay halted the executions until the state Supreme Court can hold a hearing on the inmates' lawsuit challenging the secrecy protocol surrounding the source of Oklahoma's lethal injection drugs. A hearing date has not been set.
Meanwhile, the Supreme Court rejected a request from Attorney General Scott Pruitt's office to reconsider its ruling.
The request, filed Tuesday morning, argued that the death row inmates are not entitled to the stays, that the stay order is inconsistent with well-established legal precedents and the Oklahoma Court of Criminal Appeals has exclusive jurisdiction over stays of execution.
In an emailed statement, Pruitt's director of public affairs, Aaron Cooper, said the high court's "unprecedented and extraordinary actions ... have put the state of Oklahoma in the midst of a constitutional crisis."
"We hope the Supreme Court will recognize the gravity of the constitutional crisis created by their actions and resolve the jurisdictional battle by denying the request for stays of execution from Lockett and Warner," Cooper said.
In a development reflecting the rising tension between the executive and judicial branches of state government, Gov. Mary Fallin granted a one-week stay of execution to Lockett on Tuesday afternoon, saying the Oklahoma Supreme Court overstepped its authority when it issued a separate stay.
Fallin issued an executive order delaying Lockett's execution until April 29. Fallin claims in her order that the stay issued by the state's high court is "outside the constitutional authority of that body."
Last month, Oklahoma County District Judge Patricia Parrish invalidated Oklahoma's execution law, ruling secrecy provisions that prevented the inmates from getting information about the lethal drugs that would be used in their executions violated their rights under the state constitution.
A request for a stay filed with the state Supreme Court on Monday said the inmates "have received no certifications, testing data, medical opinions or other evidence to support the state's insistence that these drugs are safe, or to prove that they were acquired legally."
The Supreme Court handed down its stay order amid a dispute among its nine justices over whether it or the state Court of Criminal Appeals should address the matter. The Supreme Court has ultimate legal authority over civil matters, while the Court of Criminal Appeals has exclusive authority in criminal appeals. The Court of Appeals on Friday denied the inmates' request for a stay, saying it didn't have authority.
State Supreme Court Justice Steven Taylor, one of four justices who dissented from the court's majority opinion, wrote that the inmates' lawsuit involves issues that are "inextricably intertwined" with criminal law and procedure.
"The appellants have maneuvered this court right where they set out to put us and that is, for the first time in this court's relevant history, in the middle of a death penalty appeal," Taylor wrote. "We have never been here before and we have no jurisdiction to be here now."