Florida has put to death a former truck driver who murdered three young women in 1986.
Convicted serial killer Oscar Ray Bolin, 53, was the first to be executed in the United States this year.
He received a lethal injection at 10.16pm (3.16am Irish time), a local prison administration official said.
Bolin was also convicted of kidnapping and rape in another case.
He appealed all his convictions and was retried for each of the killings on procedural grounds, but was again convicted.
His victims were aged 17, 25 and 26.
Bolin was equally notorious after a legal assistant on his defense team left her husband for him.
Rosalie Martinez, wife of a prominent local lawyer and mother of four children, married Bolin in 1996 when he was in prison - on live television.
She campaigned for two decades to save him.
Twenty-eight people were executed in the US last year, the lowest figure since 1991, according to the Death Penalty Information Center.