Psychopath, The (1975)

aka: An Eye For An Eye

The host of a children's TV show (Tom Basham) is really a psychopathic killer, and when he hears stories from the kids who watch his show about the abuse they get from their parents, he starts visiting the parents and murdering them. Also stars David Carlile and Barbara Grover. And with Jackson Bostwick of SHAZAM! fame.