A firing squad executed a South Carolina man who killed an off-duty police officer, the second time the rare execution method has been used by the state in the past five weeks.

For the second time in 36 days, a firing squad execution has been carried out in South Carolina. Mikal Mahdi, 42, died Friday night in Columbia less than four minutes after shots were fired. Mahdi is the 12th inmate executed in the United States this calendar year,