The , 1976 action film starring Clint Eastwood as Harry Callahan (8)
I believe the answer is:
enforcer
(Other definitions for enforcer that I've seen before include "Confrere as one who compels obedience" , "One ensures observance or compliance" , "User of strong-arm tactics to ensure compliance" , "One who compels or imposes obedience" , "Hatchet man" .)