Season 4 - Episode Guide

Follow US detectives as they reconstruct murder victims' catastrophic final hours to help catch their killers.

A killer stabs a beloved New Jersey woman 44 times in her home. Investigators have the culprit's DNA but finding him will require an assist from the FBI, a media blitz, and a random tip with details only the murderer would know.

Niagara Falls Detectives find a serial monogamist bludgeoned to death.

Alexandra Ducsay is bludgeoned to death inside her Connecticut home with her own dance trophy. Police battle to reach the truth and bring the killer to justice.

In a blue-collar Pennsylvania town, Terri Brooks-a recent college grad and assistant manager at a local chain restaurant-is strangled, beaten, stabbed, and suffocated to death at work. And within weeks, another female restaurant employee is murdered in a nearby town. At first, local detectives fear there's a serial killer on the loose. But when the second murder is solved-and Terri's case goes cold-it will take a new police chief, an autopsy of the victim's life, and more than a decade before they can finally close in on a cold-hearted killer hiding in plain sight.

A gunman strikes down beloved Cleveland Fire Department Lieutenant, William Walker, on his own driveway. Police suspect his wife's violent ex-husband, William's own ex-wife, and neighborhood enemies living closer than expected.