An award-winning journalist delves behind the scenes of a chilling true crime story aired on TV's 48 Hours—and uncovers twisting revelations inside an already shattering case of double homicide.

Halloween night in idyllic Napa, California: two young women roommates—a transplanted Southern beauty queen and a popular engineering graduate from the Napa area—are brutally stabbed by an intruder who entered their home through a first-floor window. A third roommate heard the horrific commotion but never saw the killer. News of the tragedy sent shockwaves throughout the peaceful region as well as the nation—but while investigators pursued every angle from a satanic cult to a disgruntled suitor, the murders of Leslie Mazzara and Adriane Insogna remained unsolved. Until someone came forward with a shocking confession—someone who was close enough to the women to escape suspicion. Someone who knew the victims all too well.

Complete with up-to-the-minute court action and the stunning crime scene breakthroughs that turned the case around, here is the full story of the Nightmare in Napa.