Friday's execution was the first by firing squad in modern South Carolina history and only the fourth in the U.S. since 1977. Sigmon's attorney called it a "bloody spectacle."

The last execution by firing squad in the U.S. occurred in Utah in 2010 when Ronnie Lee Gardner was executed for a 1984 murder. Utah remains the only state that has used this method since the U.S. Supreme Court reinstated the death penalty in 1976, carrying out three firing squad executions.