Prosecutors say teen killed family over prom dispute

In 1989, 9-year-old Jessica Pelley came home and learned that four members of her Indiana family were dead. Years later, her stepbrother Jeff Pelley was convicted for killing her mother, stepfather and two sisters. Prosecutors said he murdered them in anger because he was not allowed to drive himself to his prom. Jim Axelrod previews the story that will air on "48 Hours" Saturday at 10/9c.