Fallin's announcement came a day after inmate Clayton Lockett died of a heart attack 43 minutes after his execution began. Lockett's death warranted a review of the state's execution procedures, Fallin said Wednesday.
"Therefore I've also asked the Department of Public Safety and our commissioner, Michael Thompson, to lead an independent review of the state's execution procedures," Fallin said.
Fallin said the review would focus on the cause of death for Lockett's cause of death, whether the Department of Corrections followed the most up-to-date protocol for executions and necessary recommendations for improving protocols.
"I expect the review process to be deliberate, to be thorough, and it will be the first step in evaluating our state's execution protocols," Fallin said.
Fallin said she also issued an executive order Tuesday night staying the execution of Charles Warner until May 13.
"I have not given Commissioner Thompson a deadline to complete the review. If he has not completed the review by May 13, an additional stay will be issued at that time," Fallin said.