The Substitute 2: School's Out

Karl Thomasson (Treat Williams) is an ex-Green Beret turned mercenary who hasn't spoken to his brother in years, and he turns up at the funeral anyway. Randall, a teacher, was killed in a carjacking, and Karl takes a job as a substitute at Randall's school to find out what really happened. Steven Pearl puts him in front of a classroom of tough kids, a soldier who learned how to fight and never how to grieve.