A convicted double murderer is set to die by firing squad in South Carolina on Friday — the first execution of its kind in the US in 15 years.

Brad Sigmon, 67, personally requested the unusual punishment after fearing the electric chair would “burn and cook him alive,” his attorney Gerald King wrote in a statement.

He also rejected a lethal injection after three previous inmates took more than 20 minutes to die after receiving the fatal dose of pentobarbital, his lawyers said.

Sigmon became the first South Carolina inmate to choose the state’s new firing squad method of killing, and he’ll become the first inmate to be executed by shooting since 2010.

The killer will be strapped to a chair and have a hood placed over his head and a target placed over his heart in the death chamber.

Three volunteers will fire at him through a small opening about 15 feet away.

Sigmon was convicted in the 2001 baseball bat killings of his ex-girlfriend Rebecca Barbare’s parents at their home in Greenville County.

Sigmon had been smoking crack cocaine and drinking on the night of the killing, when he told a friend he would “get Becky for leaving him the way she did,” and “tie her parents up,” according to court documents.

They were in separate rooms, and Sigmon went back and forth as he beat them to death, investigators said.

The husband’s “skull was basically broken in two,” the court heard during his trial.

He then kidnapped his ex-girlfriend at gunpoint, but she escaped from his car.

He shot at her as she ran but missed, according to prosecutors.

In a confession, Sigmon said, “I couldn’t have her, I wasn’t going to let anybody else have her.”

He planned to kill both Barbare and himself, he later testified to officers.

Sigmon claimed he was forced to choose a violent death by firing squad because, without more information, he thought his alternatives would be more torturous, according to a stay of execution motion filed by his attorneys with South Carolina’s Supreme Court.

Only three inmates in the US have been executed by firing squad since 1976, with all of them taking place in Utah.

Lawyers for Sigmon asked to delay his execution date in February because they wanted to learn if the prisoner in South Carolina’s previous execution, Marion Bowman, was given two doses of pentobarbital at his execution on Jan. 31 and look over his autopsy report.

Sigmon knows it will be a violent death, his lawyer said.

“He does not wish to inflict that pain on his family, the witnesses, or the execution team. But, given South Carolina’s unnecessary and unconscionable secrecy, Brad is choosing as best he can,” King said.

Sigmon would be the oldest of the 46 South Carolina inmates who have been executed since the death penalty was restarted in the US in 1976.