The last time a firing squad was used in the United States was in 2010, when convicted murderer Ronnie Lee Gardner asked the state of Utah to execute him that way instead of by electric chair because there was “no chance of a mistake.” There are only a few states that give death row inmates this option, which critics say is inhumane and unnecessarily traumatizing for the law enforcement officers involved. But the state of South Carolina, which this month became the fourth state in the country to legalize the use of firing squads, believes firing squads could become necessary.

For the past decade, executions in South Carolina have been put on hold — not because state lawmakers were reconsidering the death penalty, but because there was a massive shortage of the lethal injection drugs needed to kill the condemned men. A new law signed by Gov. Henry McMaster will keep lethal injection as the state’s primary method of execution, and it will also require officials to use the electric chair or a firing squad if the drug shortage continues.