COLUMBIA, S.C. (AP) A South Carolina prisoner scheduled to be the first man executed in the state in more than a decade has decided to die by firing squad rather than in the electric chair later this month, according to court documents filed Friday.

Richard Bernard Moore , 57, is also the first state prisoner to face the choice of execution methods after a law went into effect last year making electrocution the default and giving inmates the option to face three prison workers with rifles instead.

Moore has spent more than two decades on death row after being convicted of the 1999 killing of convenience store clerk James Mahoney in Spartanburg. If executed as scheduled on April 29, he would be the first person put to death in the state since 2011.

The new law was prompted by the decadelong break, which corrections officials attribute to an inability to procure the drugs needed to carry out lethal injections.

In a written statement, Moore said he didnt concede that either method was legal or constitutional, but that he more strongly opposed death by electrocution and only chose the firing squad because he was required to make a choice.

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, Moore said in the statement.