A South Carolina man convicted of murder was executed by firing squad Friday, the first US prisoner to die by that method in 15 years. Three volunteer prison employees used rifles to carry out the execution of Brad Sigmon, 67, who was pronounced dead at 6.08 pm.

Sigmon killed his ex-girlfriend's parents with a baseball bat in their Greenville County home in 2001 in a botched plot to kidnap their daughter. He told police he planned to take her for a romantic weekend, then kill her and himself.

Sigmon's lawyers said he chose the firing squad because the electric chair would "cook him alive," and he feared that a lethal injection of pentobarbital into his veins would send a rush of fluid and blood into his lungs and drown him.

The details of South Carolina's lethal injection method are kept secret in South Carolina, and Sigmon unsuccessfully asked the state Supreme Court on Thursday to pause his execution because of that.

On Friday, Sigmon wore a black jumpsuit with a hood over his head and a white target with a red bullseye over his chest.

The armed prison employees stood 15 feet (4.6 meters) from where he sat in the state's death chamber - the same distance as the backboard is from the free-throw line on a basketball court. Visible in the same small room was the state's unused electric chair. The gurney used to carry out lethal injections had been rolled away.

The volunteers all fired at the same time through openings in a wall. They were not visible to about a dozen witnesses in a room separated from the chamber by bullet-resistant glass. Sigmon made several heavy breaths during the two minutes that elapsed from when the hood was placed to the shots being fired.

The shots, which sounded like they were fired at the same time, made a loud, jarring bang that caused witnesses to flinch. His arms briefly tensed when he was shot, and the target was blasted off his chest. He appeared to give another breath or two with a red stain on his chest, and small amounts of tissue could be seen from the wound during those breaths.