In every police station, there is a room filled with boxes of unsolved cases of lives cut short. Each crime is carefully preserved in what police call ‘murder books’ and somewhere in there is the key to finding a killer. Each episode follows a cold case recently solved by the determination of detectives, prosecutors, criminologists, and family members. These advocates resolutely pursue justice for little-known victims, sometimes for decades, until the killer is caught and made to answer for their crimes. Follow the twists and turns of these cases from their very beginnings, all the way through to legal resolution. Featuring interviews with investigators and family members, dramatic recreations, news, and archival footage, we find out what really happened.