Richard Moore, 57, is scheduled to be put to death on 29 April for the 1999 murder of a store clerk in Spartanburg County during a robbery gone wrong.
After being given his execution date by the Supreme Court last month, Moore was forced to make the impossible decision between the two methods of execution.
South Carolina has not executed an inmate in almost 11 years as state officials have struggled to get their hands on lethal injections used in the procedure.
This is because of both a shortage of the lethal drug cocktail and because South Carolina is not among the 14 states with laws that protect drug companies from being sued if their products are used in executions.
In order to resume executions, the state last year took the controversial step of passing a law to make electric chair the default method and to reinstate the use of firing squads.
Last month, the state corrections agency finalised the new protocols and completed $53,600 in renovations on its death chamber.
Now, inmates are given the choice between the two options.
Moore is now set to become the first inmate in South Carolina to die by firing squad and only the fourth executed using the method across the whole of the US since 1973.
In a written statement on Friday, the Black man who has spent the last two decades on death row said both options are unconstitutional but that he had been forced to make a choice by 15 April.
“I believe this election is forcing me to choose between two unconstitutional methods of execution, and I do not intend to waive any challenges to electrocution or firing squad by making an election,” he said.
The firing squad process involves three prison-volunteers shooting at the death row inmate with rifles as the inmate wears a hood over their head and a target over their heart.
The introduction of the method and the state’s resumption of executions has sparked outrage from death penalty abolition groups and human rights activisits.
Even among death penalty proponents, there are also pointed questions over whether Moore should be on death row in the first place.
The Black man has spent the last 21 years on death row after he was convicted in 2001 of the murder of James Mahoney.
In the early hours of 16 September 1999, Moore entered Nikki’s Speedy Mart convenience store in Spartanburg where Mr Mahoney was working as a store clerk.
Moore intended to rob the store for cash to pay for his drug habit and a fight broke out between the two men.
Moore was unarmed when he entered the store.
During the struggle between the two men, the store clerk pulled out a gun and Moore wrestled it from him.
Mr Mahoney then pulled out a second gun and shot Moore in the arm.
Moore returned fire, shooting Mr Mahoney fatally in the chest.
Moore has admitted to killing the store clerk but has long maintained that he acted in self defence.
He was originally given an execution date in 2020 but it was postponed because prison officials could not access the lethal injection.
Moore has exhausted almost all of his legal options and will be put to death in two weeks’ time unless a court intervenes.
On Thursday, his attorneys launched an appeal in South Carolina Circuit Court arguing that the state’s 2021 change in execution laws violated the state’s constitution.
Attorneys for four death row inmates in the state filed a lawsuit arguing that the two methods now available violate the statute banning cruel, corporal and unusual punishments while they also question the extent to which officials have tried to access lethal injection drugs.
A judge ruled on Thursday that the lawsuit can move forward.
Moore’s legal team has also asked the South Carolina Supreme Court to delay his execution so that the US Supreme Court can hear his case arguing that the penalty handed to the Black man was more severe than that given to people carrying out similar crimes.
Last week, the state Supreme Court turned down a similar appeal.
South Carolina is one of nine states that still use the electric chair and one of only four to use firing squad, according to Death Penalty Information Center.
Since 1973, three people have been executed by firing squad across the whole of the US.
The Independent and the nonprofit Responsible Business Initiative for Justice (RBIJ) have launched a joint campaign calling for an end to death penalty in the US. The RBIJ has attracted more than 150 well-known signatories to their Business Leaders Declaration Against the Death Penalty - with The Independent as the latest on the list. We join high-profile executives like Ariana Huffington, Facebook’s Sheryl Sandberg, and Virgin Group founder Sir Richard Branson as part of this initiative and are making a pledge to highlight the injustices of the death penalty in our coverage.