Whispers in the Heartland

When facing a string of gristly murders with no evidence to guide them, a small North Texas Sheriff's Department hesitatingly accepts the assistance of a Texas Ranger to help identify the killer. Executing a form of vigilante justice that seasoned officers find disturbingly brutal, the killer targets criminals that have only one thing in common; their ancestors conspired to kill the town Sheriff over a hundred years ago. The only evidence points to a supernatural perpetrator. How does modern day law enforcement stop a killer that is already dead and buried?