Man on death row chooses gruelling execution method which has only been used on four inmates in the past 50 years

A man who was handed the death penalty for the killing of a cop, as well as a store clerk, has chosen an unconventional way to complete his sentence.

The execution of death row inmate Mikal Mahdi, of South Carolina, is scheduled to be carried out on April 11, should it go ahead - with the 41-year-old granted one more chance to appeal his punishment.

Mikal Mahdi was 21 years old when he murdered two people (South Carolina Department of Corrections)

Just minutes before his death, which is set to be carried out at Columbia's Broad River Correctional Institution, Mahdi can call on Republican Governor Henry McMaster to reduce his sentence to life behind bars without parole.

However, CNN reports that no South Carolina governor has offered clemency in the 47 executions in the state since the death penalty was reinstated in 1976.

In July 2004, a 21-year-old Mahdi started his killing spree in Winston-Salem, North Carolina, taking the life of 29-year-old convenience store clerk Christopher Jason Boggs in a robbery gone wrong.

Two days later, Mahdi carjacked a man in Columbia, South Carolina, before driving to a farm in Calhoun County. It was there that he met 56-year-old off-duty police officer James Myers.

Mahdi shot him as many as eight times, two of which to the head, before dousing his body in diesel and attempting to burn him.

Myers had not long returned from an out-of town birthday celebration with his daughter, wife and sister.

Orangeburg Department of Public Safety Captain James Myers was murdered by Mahdi in 2004 (Orangeburg Police Department)

It was the cop's wife who discovered Myers' burnt body in their shed - which served as a backdrop to their wedding just 15 months prior to his death, police said.

Now, Mahdi's lawyer has spoken out about his client's choice of death - opting to die by firing squad.

"Faced with barbaric and inhumane choices, Mikal Mahdi has chosen the lesser of three evils," attorney David Weiss said in a statement, as per AP.

"Mikal chose the firing squad instead of being burned and mutilated in the electric chair, or suffering a lingering death on the lethal injection gurney."

His execution is scheduled to be carried out on April 11 (South Carolina Department of Corrections)

Should his execution go ahead, he would become the fifth death row inmate to have died by firing squad since 1976, and the second in a little over a month, with inmate Brad Sigmon completing his sentence on March 7.

According to witnesses at Sigmon's execution, three state corrections department volunteers simultaneously unloaded a round of 100-grain TAP Urban bullet each from their .308-caliber Winchester rifles.

Sigmon was hooded and wore a black jumpsuit with a target placed over his heart, and was shot while strapped to a metal chair that was sat on a catch basin.

At 6.05pm, the volunteers, who were positioned 15 feet away and hidden from the viewing area, unloaded on the 67-year-old. A doctor then examined Sigmon for about a minute and a half before declaring him dead at 6.08pm.