Lou Stark was played by Gordon Clapp in The Rage: Carrie 2.
He is a lawyer and the father of Eric Stark. As such, he is aware of the statutory rape his son committed son towards Lisa Parker, which led to her suicide and the part it played regarding the sexual game the football team has been doing in school towards girls in general.
He successfully bribes the Senior D.A. into not prosecuting his son and the football team because for their misdeeds. It is also implied the other parents are also in on this. His actions lead to the disaster of the Black Party on September 18, 1999.
It is implied that his actions will haunt him for the rest of his life.