Raiford, Florida - A 57-year-old man was executed in Florida on Thursday for a crime committed three decades ago, prison officials said.

Loran Cole was put to death by lethal injection at 6:15 PM at the Florida State Prison in Raiford, the Florida Department of Corrections said in a statement.

Cole was sentenced to death in December 1995 for the February 1994 murder of an 18-year-old Florida State University student, who was on a camping trip with his sister in the Ocala National Forest.

Cole was also convicted of sexually assaulting the murder victim's elder sister, who was tied to a tree but managed to escape the next day.

An accomplice, William Paul, was sentenced to life in prison.

"Tonight we killed the man responsible for the death of John Edwards. And we also killed a father, a son, a brother, a friend. We grieve with all of Loran’s loved ones. We do not minimize the harm he caused, and we also grieve with his victims and their loved ones," Floridians for Alternatives to the Death Penalty said in a statement, which went on to lay out the extreme challenges advocates faced in understanding why Loran was chosen for the death penalty and reaching the governor to share petitions against his execution.

"A selection process shrouded in secrecy. No way for the public to make its voice heard. Key officials unavailable the week we are killing a human being. This is no system of orderly justice," the statement continued. "We the people of the State of Florida deserve and demand better."

The US Supreme Court denied Thursday afternoon – without comment – Cole's appeal to stay his execution on the grounds he had Parkinson's disease and the lethal injection would "very likely cause him needless pain and suffering."

There have been 13 executions in the US this year. The death penalty has been abolished in 23 states, while six others – Arizona, California, Ohio, Oregon, Pennsylvania, and Tennessee – have moratoriums in place.