When we wake up to new tragedies in the news every day—shootings, rampages, acts of domestic terrorism- we often blame ourselves for missing the mania lurking inside unsuspecting individuals. But how could we have known that the charismatic leader had the characteristics of a tyrant? And how can ordinary people identify threats from those who are poised to devastate their lives on a daily basis—the crazy coworkers, out-of-control family members, or relentless neighbors?