Criminal profilers and neurological experts weigh in on what drives serial killers and whether certain people are predisposed to murder.
Why do they do it and how do they get away with it? Step into the minds of history's most heinous kidnappers, including Ariel Castro and Josef Fritzl.
Though cults take on many different forms, they all tend to have one thing in common: an all-powerful leader whose word cannot be questioned.
Crime lords John Gotti, Pablo Escobar, El Chapo and Al Capone capture the public's admiration despite -- or because of -- their heinous acts.