Updated

Oklahoma and Florida executed death row inmates twelve minutes apart Thursday, with both states employing the same three-drug cocktail that was used in a botched lethal injection in Oklahoma last April.

In Oklahoma, prison officials declared Charles Frederick Warner dead at 7:28 p.m. CST Thursday. The execution lasted 18 minutes.

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

Warner, 47, was executed for killing his roommate's infant daughter in Oklahoma City in 1997. He 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.

After the first drug was administered, Warner said, "My body is on fire." But he showed no obvious signs of distress.

Witnesses told the Associated Press they saw slight twitching in Warner's neck about three minutes after the lethal injection began. The twitching lasted about seven minutes until he stopped breathing.

It was the second time Oklahoma used the sedative 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 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 Florida, 42-year-old Johnny Shane Kormondy was executed for killing a man during a 1993 home invasion robbery. Cecilia McAdams, the wife of the murdered man, watched Kormondy die and said afterward, "My family and I have waited 21 long years for this day to happen ... He needed to die." The AP typically does not name victims of certain crimes, but she has spoken openly about her rape at the hands of Kormondy and his accomplices and her husband's death. She has also done extensive work on behalf of other victims.

Oklahoma increased by five times the amount of the sedative it planned to use to mirror the exact recipe that Florida had used in 11 successful executions.

Midazolam also was used in problematic executions last year in Arizona and Ohio, however. Inmates snorted and gasped during those lethal injections that took longer than expected.

Oklahoma Attorney General Scott Pruitt has acknowledged that midazolam is not Oklahoma's first choice to be used in lethal injections. But he said prison officials have been unable to secure other, more effective drugs because the manufacturers oppose their use in executions.

After Lockett's execution was botched, a state investigation determined that a single intravenous line failed and that the drugs were administered locally instead of directly into his bloodstream.

Since then, Oklahoma has 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.

The Associated Press contributed to this report.