When I worked with former FBI profiler Mary Ellen O’Toole, PhD, I had nightmares. She told me everything she’d learned from interviewing the Green River Killer and many other serial killers and psychopaths. The result, Dangerous Instincts, teaches readers how to use the tools of a profiler to read people, make decisions and more. It resulted in national publicity on Fox & Friends, NPR, the Washington Post and many other outlets.