The Supreme Court of South Carolina on Wednesday issued a stay of execution for a death row inmate, temporarily halting what would have been the state’s first firing squad execution in its history. Richard Moore, 57, had been scheduled to be shot dead on April 29 after being convicted of murdering a convenience store clerk in 1999. After more than two decades spent on death row, Moore opted for execution by firing squad over the electric chair, saying that he believed he was being “forced… to choose between two unconstitutional methods of execution.” On Wednesday, the state’s highest court said in issuing the stay that it would elaborate in a more detailed order to come. Moore’s defense team had previously sought a halt to the execution, arguing that the constitutionality of the state’s executions was under question, with a legal challenge to its methods currently pending in another court. If the execution is carried out, Moore will become only the fourth person to die by firing squad in the U.S. since 1976. He would be the first person put to death in South Carolina in more than a decade.