When Captain Awkward and Ask a Manager both repeatedly recommend a book, ya gotta read it.
Here's what I wish someone had told me before I read this - if you want to learn about using intuition to protect yourself, and get some insight into red flags from strangers, co-workers, dates, etc., there is some amazing stuff in here, but it's salted in among a lot of other content, from a clinical discussion of risk assessment on a more mathematical level, to detailed stories of disturbed people committing suicide, murder, and assassinations.
Now, those chapters and sections are fascinating in their own way, but not what I was looking for, and for me way too depressing to justify the “Wow, that is an intriguing story” aspect. (At another time, I would actually be really interested to read a biography of Gavin de Becker, and an in-depth description of how his firm works and all the crazy cases they've handled, because it does sound fascinating in its own way, if you can handle the sadness/horror of the stories.)
Still, there's amazing information about how potentially dangerous people test, groom, and ensnare victims, the warning signs of a violent work incident and how management can mitigate the risk, and even a list of questions to ask your school about student safety. Lots of good practical advice that can make people be safer while feeling less afraid.
Finally, there's some wonderful information about setting boundaries, how women are socialized to interact, and what the warning signs are that a romantic interest is really bad news. I'm definitely excerpting this stuff for my kids when they start dating!