The most terrifying criminals often hide in plain sight, looking as ordinary as a friendly next-door neighbor. Those regular Joes are the focus of "American Monster," precisely because lurking within them are psychopathic killers. Similar to Investigation Discovery's "See No Evil," the hourlong series uses personal movie footage of the monsters-in-disguise at home with family and friends, giving viewers a sense of how their lives are seemingly normal. Interweaved are the stories of their astonishing crimes and interviews with neighbors and loved ones.