In August 1989, Troy Davis, then 19 years old, was involved in the murder of an off-duty police officer at a bus station in Savannah. After a homeless man named Larry Young was pistol-whipped from behind, 27-year-old Officer Mark MacPhail, who was working a security job, chased Davis and two buddies, one of whom was a man named Sylvester Coles. Witnesses said that MacPhail’s murderer stopped r…