South Carolina Supreme Court halts firing squad execution

April 20 (UPI) -- The South Carolina Supreme Court on Wednesday issued a temporary stay for what was planned to be its first execution in more than a decade.

Richard Moore, 57, was scheduled to be executed April 29 for the 1999 murder of convenience store clerk James Mahoney during a robbery. He chose to die by firing squad instead of the electric chair, his only two options.

The state's highest court issued the temporary stay in response to a challenge by Moore's lawyers, who said South Carolina's execution methods are unconstitutional. They also said Moore's punishment was disproportionate for his crime.

The South Carolina Department of Corrections announced last month that death row prisoners now have the option of choosing to be put to death by firing squad, in addition to the electric chair, the state's primary means of execution.

The state hasn't carried out an execution since 2011 when its supply of lethal injection drugs expired. Many states have had difficulties sourcing drugs for the execution method after European countries decided to stop selling them for this purpose and many U.S. companies refused to sell them if they're identified.