Perfect on the outside, mental on the inside. Even the most kind-hearted people have a dark side looming. Diabolical looks at the minds of murderers with the question: "why did they do it?" Take a trip through the picture-perfect life and see the events that lead to a brutal murder. The tension builds throughout each episode as you dive deeper into the psychological workings of the murderer. With key insights from forensic psychologists and psychiatrists along with criminal profilers, a full analysis of the behavioral underpinnings and key moments in each crime will be on display. Diabolical shows how much people can conceal, until they blow.