McALESTER, Okla. » Oklahoma executed a death row inmate Thursday in its first lethal injection since a botched one last spring, and it carried out the punishment with a three-drug method that Florida used for an execution the same night.

Charles Frederick Warner’s execution for the 1997 killing of an 11-month-old girl in Oklahoma City lasted 18 minutes. Prison officials declared him dead at 7:28 p.m. CST.

Meanwhile, officials in Florida announced the death of Johnny Shane Kormondy at 8:16 p.m. EST for killing a man in 1993 in Pensacola. The executions, which occurred 12 minutes apart, were both delayed over court questions concerning the drugs used in the punishments.

"Before I give my final statement, I’ll tell you they poked me five times. It hurt. It feels like acid," Warner said before his execution began. He added, "I’m not a monster. I didn’t do everything they said I did."

After the first drug, the sedative midazolam, was administered and a microphone inside the death chamber was turned off, Warner said, "My body is on fire." But he showed no obvious signs of distress.

Witnesses said they saw slight twitching in Warner’s neck about three minutes after the lethal injection started. The twitching lasted about seven minutes until he stopped breathing.

Warner’s attorney, Madeline Cohen, who witnessed the execution, said there was no way to know if Warner suffered because the second drug, a paralytic, would have prevented him from moving.

"Because Oklahoma injected Mr. Warner with a paralytic tonight, acting as a chemical veil, we will never know whether he experienced the intense pain of suffocation and burning that would result from injecting a conscious person with rocuronium bromide and potassium chloride," Cohen said in a statement.

Gov. Mary Fallin issued a statement praising the professionalism of the prison staff.

"Justice was served tonight as the state executed Charles Warner for the heinous crime of raping and murdering an infant," Fallin said.

It was the second time Oklahoma used midazolam as part of a three-drug method, which had been challenged by Warner and other death row inmates as presenting an unconstitutional risk of pain and suffering.

The execution came after a divided U.S. Supreme Court in a 5-4 ruling said it wouldn’t consider whether a sedative given to the inmate would be strong enough to render him so unconscious that he wouldn’t feel other drugs stop his lungs and heart.

In a dissenting opinion, Justice Sonia Sotomayor said she believes questions about the effectiveness of the drugs are particularly important because of states’ increasing reliance on new and scientifically untested methods of execution.

"Petitioners have committed horrific crimes, and should be punished," Sotomayor wrote. "But the Eighth Amendment guarantees that no one should be subjected to an execution that causes searing, unnecessary pain before death."

Warner, 47, was originally scheduled to be executed in April on the same night as Clayton Lockett, who began writhing on the gurney, moaning and trying to lift his head after he’d been declared unconscious.

A state investigation determined that a single intravenous line failed and that the drugs were administered locally instead of directly into Lockett’s bloodstream. Oklahoma put its executions on hold for nine months after the problematic execution.

Prison officials called for more extensive training of staff. They also ordered new medical equipment, such as backup IV lines and an ultrasound machine for finding veins, and renovated the execution chamber with new audio and video equipment to help the execution team spot potential problems.

Oklahoma also changed its method for administering the drugs to match Florida’s, increasing by five times the amount of midazolam. Florida has used the same recipe in nearly a dozen successful executions, including Thursday’s.

Midazolam, however, was used in problematic executions last year in Arizona and Ohio, and Oklahoma Attorney General Scott Pruitt has acknowledged that the drug is not his state’s first choice for its lethal injections.

But Pruitt said prison officials have been unable to secure other, more effective drugs because the manufacturers oppose their use in executions.