Sheriff Len Hagaman of Watauga County in North Carolina says the shooter who killed two deputies and two civilians in Boone this week also threatened his father with a knife recently.

The alleged assault prompted Isaac Alton Barnes’ family to go to a magistrate for assistance.

The father also called the county sheriff’s office for help.

Barnes, his mother and stepfather were found dead after a 13-hour standoff with police.

Sgt. Chris Ward and K-9 Deputy Logan Fox were killed in the line of duty. Funeral arrangements for the fallen deputies were recently announced.

Hagaman says Barnes had a “large cache” of weapons and could have killed more people through a mass shooting targeting the general public.