Death row inmate Marcus Wellons is seen in an undated handout from the Georgia Department of Corrections.
Two convicted murderers, one in Georgia and the other in Missouri, were put to death barely an hour apart in the first U.S. executions since a botched lethal injection in Oklahoma in April renewed a national debate over capital punishment.
Georgia inmate Marcus Wellons, 58, convicted of the 1989 rape and strangulation of a 15-year-old neighbor he abducted while she was walking to her school bus stop, was executed by lethal injection at 11:56 p.m. local time.
State corrections spokeswoman Gwendolyn Hogan said Wellons made a statement of apology and recited a short prayer just before his execution at a prison intake facility in Jackson, Georgia. The procedure went smoothly, she said.
A little more than an hour later at a Missouri state prison in Bonne Terre, John Winfield, 46, met the same fate for killing two women and leaving his ex-girlfriend blind and disfigured in a 1996 rampage.
Winfield, who declined a final meal and made no last statement, was pronounced dead at 12:10 a.m., Missouri Department of Public Safety spokesman Mike O'Connell said.
In both cases, the executions proceeded shortly after the U.S. Supreme Court denied multiple applications from the inmates seeking 11th-hour reprieves. A third inmate in Florida was due to be executed on Wednesday.
The cases of Wellons and Winfield drew greater attention than most as they were the first put to death since Oklahoma killer and rapist Clayton Lockett died on April 29 in a mishandled execution that sparked an uproar among opponents of the death penalty put a spotlight on capital punishment.
Lockett suffered an apparent heart attack and died about 30 minutes after Oklahoma prison officials had halted his execution because of problems in administering the lethal injection. A preliminary autopsy released by his lawyers last week showed the state failed to properly insert an intravenous line to deliver the fatal dose of medication.
Even the White House criticized the bungled execution as failing to adhere to humane standards.
Wellons was the first person executed in Georgia since the state's Supreme Court upheld a law in May shielding the identity and methods of pharmacies that make its lethal injection drugs.
Attorneys for the state said the execution protocol has not changed since 2012, when Georgia switched from a three-drug cocktail to a single drug, pentobarbital. Oklahoma used a new three-drug cocktail for Lockett's execution.
In his appeal to the Supreme Court, Wellons' attorneys cited the Oklahoma case to bolster their argument that Georgia had not provided enough detail about the state's execution protocol.
Winfield's lawyers likewise argued in court filings that Missouri's secrecy about where it gets its lethal injection drugs and how they are made were grounds for a stay.
Wellons and Winfield brought the number of executions in the United States this year to 22, according to the non-profit Death Penalty Information Center.