A 57-year-old man, Gary Ray Bowles who admitted to killing six gay men in 1994 from Florida to Maryland has been executed.
Investigators say Bowles left an abusive household as a child and worked as a prostitute to gay men for a number of years before beginning his killing spree.
After two jail sentences for grand theft, robbery, assault and rape, he moved to Daytona Beach in 1993.
During this time he continued to work as a prostitute, and was living with a girlfriend who left him after discovering his sex work.
He later told authorities that he blamed gay men for their break-up, and was angered to learn that his girlfriend had done an abortion.
He is the 13th person to be executed in the US so far this year, the Death Penalty Information Center says.