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.

Examines the 20 of the most shocking unsolved crimes in history including the disappearance of Adam Walsh, the murder of Jam-Master Jay, the murders of Jason Allen and Lindsay Cutshall, the Tylenol Poisoning scare, the mysterious death of musician Bobby Fuller, the Zodiac Killer, the assassination of spy Alexander Litvinenko, the murder of Vanessa Johnson, the murder of Amber Hagerman, the Isabella Stewart Gardner Museum Robbery, the disappearance of George Allen Smith, disappearance of heiress Jacqueline Levitz, the disappearance of Madeleine McCann, the 2001 Anthrax attacks, the D.B Cooper skyjacking, the murder of Chandra Levy, the disappearance of Jimmy Hoffa, the murder of the Black Dahlia, the murder of JonBenet Ramsey, and the disappearance of Natalee Holloway.

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.