US states overnight Tuesday carried out the first two executions since a botched one in April that caused a prisoner to suffer and triggered a hot debate on lethal injection.
A mug shot obtained April 30, 2014 from the Oklahoma Department of Corrections shows convicted murderer and rapist Clayton Lockett, whose death by a botched lethal injection triggered an outcry
On Tuesday and early Wednesday one execution was in Georgia and the other in Missouri. Both were also by lethal injection and came after last-minute appeals were rejected by the US Supreme Court.
In the first of them, Marcus Wellons, 58, convicted of the 1989 kidnapping, rape and murder of a 15-year-old girl, was put to death shortly before midnight in the southern state of Georgia, a spokesman for the prison system said.
In the second case, John Winfield, 43, convicted of killing two women, was executed in the central state of Missouri, state prison system spokesman Mike O'Connell said.
They were the first since the botched April 29 execution in Oklahoma.
Clayton Lockett, a convicted killer and rapist, was then put to death by lethal injection in a process that took 43 minutes, well over the usual time of a little over 10 minutes.
He was seen writhing in pain, bucking off the gurney and mumbling unintelligibly in a spectacle that drew widespread condemnation, even from President Barack Obama.
Obama, who backs the death penalty for heinous crimes, condemned the incident as "deeply troubling."
He ordered Attorney General Eric Holder, who is seeking the death penalty in the Boston Marathon bombings case, to conduct a policy review of how the death penalty is applied in the United States.
Since then five executions slated to take place had been delayed, including the two carried out overnight Tuesday, as states reviewed their execution procedures.
The appeals to prevent the two latest executions centered on secrecy surrounding the lethal injection procedure, the origin of the drugs used and whether the people carrying out the sentences were truly qualified.
A third execution was also scheduled for 6:00 pm (2200 GMT) Wednesday in the southern state of Florida.
In that case, John Henry, 63, is being sentenced to death for killing his wife and her five-year-old son in 1985. At the time he was out on probation over the killing of his first wife.
-- Drug shortages --
US states using the death penalty have faced crises over shortages of lethal injection drugs after European suppliers stopped supplying pentobarbital for use in executions.
The shortages have prompted prison departments in the 32 states that still allow the death penalty to seek new supply sources or cocktails of drugs to conduct executions.
After the botched execution in April, Oklahoma suspended the procedure for six months as it reviews its practices and probes the case of Lockett.
A week after that execution, a report said US states were increasingly attempting to conceal information about drugs used to perform lethal injections.
Death penalty states "have intensified their efforts to obscure information regarding the development and implementation of their lethal injection protocols," said the report by a committee of experts convened by the Constitution Project, a non-profit group that promotes bipartisan consensus on legal reform.
"This poses an unacceptable risk that inmates will face an unnecessarily cruel and painful death, violative of the US Constitution," the 208-page study said, calling for comprehensive US capital punishment reform.
The new executions were the 21st and 22nd so far this year in the United States.