The state of Florida on Thursday executed a serial killer who preyed on older gay men.

According to the AP, Gary Ray Bowles was executed by lethal injection.

Bowles is known to have killed six men during an eight-month killing spree in 1994. He was known as the “I-95 killer” because most of his victims across three states lived close to Interstate 95, which runs from Florida to New England.

Bowles, 57, left West Virginia at the age of 13 after he fought back against his second abusive stepfather, whom he nearly killed by smashing a rock in his head. While Bowles maintained that he's straight, he survived by charging gay men for sex.

“I had a question about him being gay. He told me he was not, and I said, 'What do you describe yourself as?' He said, 'A hustler,'” said Thomas Youngman, a Daytona Beach detective. “He'd befriend these old guys and have sexual relations with them, but I think they performed on him. He said he did not perform on them.”

Bowles had a calling card. In each case, he stuffed his victims' throats with objects such as towels, rags and even a sex toy.

Bowles served eight years in prison for the 1982 beating and raping of his girlfriend.

Former Savannah detective John Best told the AP that Bowles freely admitted to killing his male victims, but refused to say whether he also murdered women.