US inmate set to die by firing squad, which states allow this?

(NEXSTAR) - A South Carolina death row inmate is set to be executed on Friday, March 7. Instead of the more traditional lethal injection, the inmate—Brad Sigmon, 67—has chosen to die by firing squad, a method that has only been performed three times in the last 49 years.Sigmon, who is being executed for the 2001 killings of his ex-girlfriend’s parents at their home in Greenville County, chose to forego lethal injection due to concerns that little is known about the drugs or pro