When 18-year-old Lisa Monza is murdered in San Lorenzo, California, investigators look for a connection to other unsolved murders in the area. But it will take several years and help from an unlikely source before they can track down her killer.

A widow is murdered in her Salt Lake City home. Despite suspicion that the victim was murdered by someone she knew, the case goes cold for two decades, until a set of children's fingerprints leads to the killer.

Just weeks from graduation, popular high school senior Marlys Wohlenhaus is bludgeoned to death in her family's Minnesota farmhouse. Investigators suspect the 18-year-old knew her killer, and though family members report she was distracted in the days leading up to the attack, no one knows what was troubling Marlys. Initially, Marlys' violent ex-stepdad emerges as the number-one suspect. Detectives believe he hired a hitman who mistakenly killed Marlys instead of her mother, but it's a dead end and the case soon goes cold. Fifteen years later, a fresh set of eyes spots an overlooked clue. But cold case detectives will need more to convict the killer. And it will take a mother's love and a TV interview before a sinister rap sheet can deliver justice for Marlys. Initially, Marlys' violent ex-stepdad emerges as the number-one suspect. Detectives believe he hired a hitman who mistakenly killed Marlys instead of her mother, but it's a dead end and the case soon goes cold. Fifteen years ...

On a quiet summer evening in New Hampshire, 63-year-old Robert Cushing answers a knock at the door and is shot dead through the screen. No evidence is found at the scene, and investigators in the sleepy seaside town face a big-city murder investigation. They have no suspects, no motive, and no idea why anyone would want to kill the retired popular schoolteacher and devoted father of seven. That is, until they uncover a seething grudge and a culprit closer to home than anyone could have imagined.

Deep in Southern Louisiana, the bodies start piling up in a series of deadly home invasions. There's a curious link between the victims and a similar MO, and before long a combined task force is on the hunt for a serial killer.