The House That Screamed (1969). Lilli Palmer owns and runs a school for wayward girls. Her absolute discipline has fostered a social order among the girls with rampant sex, lesbianism and torture the norm. Palmer also has an adolescent son she tries to keep isolated from the women lest he be tainted by sexual relations. She explains that he must wait for a girl "just like his mother". Meanwhile, girls are "running away" (murdered) one by one, with their corpses not to be found.
The Last House on the Left (1972). A pair of teenage girls are headed to a rock concert for one's birthday. While trying to score marijuana in the city, the girls are kidnapped by a gang of psychotic convicts.
Bad Ronald (TV Movie 1974). Scott Jacoby, a nerdy high school youth, accidently kills a neighbor's young daughter. Panicking mother, Kim Hunter, fears the police will not believe that it was an accident. She moves her son into a bathroom that she turned into a secret hiding place. After her death, a new family moves in. In the mean time, Ronald has gotten lost in a fantasy world created in his own head from being hidden away for so long.