Oklahoma on Thursday executed its first death row inmate since a botched lethal injection in April forced the state to revise its policies. Charles Warner, who was convicted in the 1990s on charges he sexually assaulted and killed an infant, died at 7:28 p.m., local time.

Upon being injected with the first drug, Warner said his body felt like it was on fire, but the Associated Press reported he did not indicate he was in further distress. Warner took 18 minutes to die.

Warner was supposed to be executed last April, on the night Clayton Lockett started moving and speaking after receiving lethal drugs. Lockett's IV connection reportedly failed, releasing drugs into the tissue around his groin, and he died of a heart attack 43 minutes into the execution.

The incident caused several prisoners' lawyers to argue that the state's sedative of choice, midazolam, was not reliable enough to use. Warner's attorneys said the sedative wasn't strong enough to ensure the man wouldn't feel the other injections stop his heart, but the U.S. Supreme Court voted 5-4 against intervening.

"The questions before us are especially important now, given States’ increasing reliance on new and scientifically untested methods of execution," dissenting Justice Sonia Sotomayor wrote. "Petitioners have committed horrific crimes, and should be punished. But the Eighth Amendment guarantees that no one should be subjected to an execution that causes searing, unnecessary pain before death. I hope that our failure to act today does not portend our unwillingness to consider these questions."

Between Lockett's death and Thursday, Oklahoma reformed its drug policies, remodeled its execution chamber to have better video equipment and updated training for executioners, Time reportedIn Warner's execution Thursday, doctors used five times the amount of midazolam they previously did as well as new ultrasound equipment that helped with IV placement. Johnny Shane Kormondy, who allegedly killed a man in 1993, was executed the same way in Florida on Thursday.