COLUMBIA, S.C. (AP) — A South Carolina man who is scheduled to die next week by firing squad is again asking that his execution be postponed and prison officials release more information about the state’s lethal injection drug and procedures.

Condemned South Carolina inmate Brad Sigmon has chosen to die next month by a firing squad, a method of execution that has not been used in the U.S. in 15 years.

During the Civil War, both sides used firing squads to kill deserting soldiers. Today, people on death row can choose to die that way in some states.

Brad Sigmon, set for execution by firing squad on March 7, seeks a delay, citing concerns over South Carolina’s lethal injection process. If carried out, it would be the first U.S. firing squad execution since 2010.

Brad Keith Sigmon is set to be executed by firing squad on March 7 for the 2001 beating deaths of his ex-girlfriend's parents, David and Gladys Larke.

The state has never used that method to execute a prisoner. The last time an inmate was killed by a firing squad was in 2010 in Utah.

The South Carolina Department of Corrections shared an overview of the protocols ahead of the state's first firing squad execution.