John Winfield was executed at the state prison in Bonne Terre by lethal injection at 12:01 a.m. and was pronounced dead at 12:10 a.m., a spokesman for the Department of Public Safety said.
Winfield, 46, took four or five deep breaths as the drug was injected, puffed his cheeks twice and then fell silent, all in a matter of a few seconds.
Winfield shot Carmelita Donald, his ex-girlfriend and the mother of two of his children, in the head, leaving her blind. He also shot and killed two of her friends, Arthea Sanders and Shawnee Murphy.
Winfield declined to make a final statement or eat a final meal. Donald was among those witnessing the execution. She and other witnesses declined to comment.
Winfield's execution came shortly after convicted killer Marcus Wellons was put to death in Georgia. Wellons' execution was the first in the nation since a botched execution on April 29 in Oklahoma raised new concerns about lethal injection.
Winfield's attorneys had appealed to the U.S. Supreme Court over concerns that a prison worker dropped plans to write a letter in support of clemency due to intimidation from staff, and over concerns about the secretive process Missouri uses to obtain its lethal injection drug. But the Supreme Court refused late Tuesday to halt the execution, and moments later, Gov. Jay Nixon denied clemency.
Missouri Attorney General Chris Koster issued a statement after the execution, saying that: "Nearly two decades have passed since John Winfield's cowardly acts of rage and jealously changed the lives of three families forever. ... For his actions, a court lawfully sentenced him to death under Missouri law, and tonight that sentence has been carried out."
Another convicted killer, John Ruthell Henry, is scheduled to die later Wednesday in Florida.
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