The murder of a young Hollywood actress Elizabeth Short in 1947 is the oldest unsolved murder case in Los Angeles. New information and clues may help solve this case. "48 Hours Mystery" correspondent Erin Moriarty reports.

The unexplained deaths of Elizabeth Short, a.k.a "The Black Dahlia", in 1947 and of Geneva Hilliker Ellroy in 1958, had a profound impact on the psyche of James Ellroy, today's greatest crime writer. Steve Hodel, a retired LAPD cop, reveals everything about Georges Hodel, his own father as well as the perpetratror of those two unsolved murders, the most notorious ones in 20th century America. Steve Hodel retraces this amazing investigation in which genius and horror, Hollywood and the Marquis de Sade, incest and surgery, are blended into the grimmest of scenarios.