Washington: A man was executed on Wednesday in the US state of Missouri for the rape and murder of a teenage girl, authorities said.
It was the fifth execution in as many months in the mid-western state using a controversial chemical for lethal injections.
Jeffrey Ferguson, 59, was declared dead by a lethal dose of pentobarbital at 11 minutes after midnight (05H11 GMT), said Mike O'Connell, spokesman for the Missouri Department of Public Safety.
Ferguson was condemned to death for the abduction, rape and killing of a 17-year-old girl in 1989 in a suburb of St. Louis.
The girl's body was found 13 days after her kidnapping from a gas station where she had worked.
An accomplice pleaded guilty and was sentenced to life in jail with the possibility of parole.
Ferguson "was alcoholic" at the time of the crime but "changed a lot" in prison, said his attorney, Jen Herndon.
"He's very religious, he's ready to go, more ready than any other of my clients," Herndon told AFP shortly before the execution.
In his final appeals, which went all the way to the US Supreme Court, Ferguson said the anesthetic with which he was to be put to death were manufactured by a company not certified by the federal government and whose name the state of Missouri refused to disclose.
He argued that the injection with pentobarbital could subject him to suffering that violated the constitutional ban on cruel and unusual punishment, according to court documents.
Since European manufacturers started refusing to supply US states with the usual chemicals used in US executions, Missouri has joined other states in turning to suppliers not certified by the US government.
This was the fifth execution in five months in Missouri with a chemical produced by a manufacturer not certified by the US government.
Another is planned for April.
Ferguson's execution was the 13th this year in the United States.
Another is scheduled for Wednesday in Texas.