Fifty years ago, a serial killer prowled the quiet city of London, Ontario, marking it as his hunting grounds. As young women and boys were abducted, raped, and murdered, residents of the area held their loved ones closer and closer, terrified of the monster -- or monsters -- stalking the streets. Homicide detective Dennis Alsop began hunting the killer in the 1960s, and he didn't stop searching until his death 40 years later. For decades, detectives, actual and armchair, and the victims' families and friends continued to ask questions: Who was the Forest City Killer? Was there more than one person, or did a depraved individual commit all of these crimes on his own? Combing through the files Detective Alsop left behind, researcher Vanessa Brown reopens the cases, revealing previously unpublished witness statements, details of evidence, and astonishing revelations. And through her investigation, Vanessa posits the unthinkable: is it possible that the Forest City Killer is still alive and, like the notorious Golden State Killer, a simple DNA test could bring him to justice?