Grayson’s three accomplices managed to escape execution because they were under 18 at the time of Deblieux’s murder

The execution is the 22nd in the U.S. this year and the sixth in Alabama, which has put three of the men to death using nitrogen gas.

Grayson was one of four teenagers convicted of capital murder in the torture, bludgeoning and mutilation of Vickie Lynn Deblieux on Feb. 21, 1994.