2x4 - Most Evil

Dr. Stone's scale of evil has decoded the complex psychology of the country's most notorious criminals. But can it be used to reveal new clues for unsolved crimes? Cold cases, including that of the infamous Black Dahlia, will be reopened as Dr. Stone profiles killers who may still be at large. He'll venture into prison to meet face-to-face with alleged Lipstick Murderer Bill Heirens.