Lockett and Warner's executions had already caused a constitutional crisis in Oklahoma as their execution date neared. On April 21, the Oklahoma Supreme Court intervened and stayed both defendants' executions amid concerns about a state-secrecy law that shielded the identities of lethal injection drug suppliers from activists, defendants, and the public. The surprise move—Oklahoma's supreme court does not normally hear criminal cases—sparked outrage among the state's elected politicians. Governor Fallin, a Republican, issued an executive order the next day that scheduled a new execution date in direct defiance of the court's stay. State legislators also drafted a resolution to impeach the justices who delayed the execution. The court, whose nine justices include six Democratic appointees, backed down the next day and upheld the secrecy law as constitutional.

Political considerations deeply shape the death penalty in Oklahoma, where it remains popular even amid a nationwide decline in support. Two months after Lockett's botched execution, a Tulsa World poll found that 74 percent of Oklahomans support the death penalty. (The national average hovers somewhere around 60 percent.) According to court documents, the state attorney general's office recommended the drug to Michael Oakley, the department of corrections' general counsel at the time, when the standard lethal-injection drugs couldn't be obtained.

“[T]he Attorney General’s office, being an elective office, was under a lot of pressure,” Oakley testified. “The staff over there was under a lot of pressure to say, ‘Get it done,’ you know.” Oakley, who has no medical training, testified that he approved the drug after consulting general counsels in other states and Wikipedia.

I did have a discussion with our medical director at the time and he said, "Yeah Midazolam probably when administered will, will render sedation." And that’s all he would say. Then, you know, I did my own research, I looked on-line, you know. Went past the key Wiki leaks, Wiki leaks or whatever it is, and I did find out that when administered, Midazolam would administer, would render a person unconscious. That’s what we needed … So we thought it was okay.

Warner's lawyers contend that midazolam isn't an acceptable substitute for sodium thiopental, the standard anesthetic used in lethal injections. They make a compelling case.

Although Oklahoma uses it for sedation in executions, the FDA doesn't even approve the use of midazolam as the sole anesthetic in standard surgical procedures. Because the drug has a ceiling effect, increasing the dosage does not necessarily increase its effectiveness. In Arizona's botched execution of Joseph Wood last July, where he spent nearly two hours gasping for air in apparent agony before finally dying, the state's two-drug protocol used 750 ml of midazolam, a full seven-and-a-half times more than Oklahoma used on Lockett last year and 250 ml more than what will be used in Warner's execution tonight.