48 Hours: Season 18, Episode 9

18 - 9: Nightmare in Napa

It's a real-life Halloween shocker in idyllic Napa, Calif. when two young women are brutally murdered in 2004. Just hours after the last trick-or-treater left their home, former beauty queen Leslie Mazzara and her roommate, Adriane Insogna, were found stabbed to death in their upstairs bedrooms. A third roommate, sleeping downstairs, was not harmed and was the only witness. Who wanted these young women dead? After almost a year of heavy investigating, one clue turns this case inside out and leads to an unlikely suspect who was overlooked by investigators.