The key to solving the toughest homicides lies somewhere in the final hours of a victim's life. In each one-hour episode, determined investigators must piece together events during this critical window to reconstruct the timeline, unlock the motive, and ultimately close in on the killer.

A wild and unpredictable journey into homicide investigations where the true identity of the killer comes as a shocking surprise. Combining unparalleled access, captivating interviews and stylish reenactments, each investigation starts in a familiar way - examining the crime scene, interviewing potential suspects… but then something unexpected changes everything. A new witness, an overlooked piece of evidence or even an innovation in forensic science sends investigators on a totally unexpected path that ultimately leads to the conviction of the real killer.