He and common-law wife
Lynda Lyon were convicted of the 1993 death of Opelika, AL police officer Roger Motley, son of
Anne Motley. Sibley engaged Motley in a fire fight in the parking lot of Pepperell Corners Shopping Center after Motley approached Sibley to inquire about the well-being of Lyon's 9 year old son, who was traveling with them. Lyon, who was at a pay phone when the fire fight broke out, shot at Motley as she ran toward him. Members of an anti-government movement, Lyon and Sibley were fleeing authorities in Florida for failing to appear in court to face charges of assaulting Lyon's estranged husband. Both said they acted in self-defense. Lyon, who refused to cooperate with her attorneys and maintained that Alabama had no right to try her because it had not been properly readmitted into the Union after the Civil War, was executed in 2002.