Each year the FBI estimates between 25 to 50 active serial killers hunt their prey in America, taking the lives of hundreds of innocent people annually. Often these killings keep a city on edge, a heavy fear permeating the night air before these predators are taken off our streets. Just ask those who lived through the terror of The Night Stalker, Son of Sam or The Grim Sleeper. And years later the public still can't seem to get enough of their stories which continue to be retold in documentaries and limited series. Yet for every Jeffrey Dahmer or Ted Bundy who became part of the zeitgeist and remains with us like a dark specter, there are hundreds of other unknown serial killers whose horrific actions were just as terrifying, if not worse. This new series will profile these unknown serial killers who operated in silence. Their murders haunted law enforcement, who were unable to connect all their sick dots, as more innocent lives were lost until the killers were eventually caught.