This important, riveting book explores the troubled minds of mass killers through their own words. Author David J. Krajicek examines the leavings of some 50 killers from the United States and Europe, both contemporary and historical. Some are humble, some grandiose--from brief, introspective suicide notes to long whines by sex-deprived men. A few are poignant and thoughtful, and others reek of narcissism, like the ultimate selfie. They range in length from an eerie, five-word message left by a Michigan school bomber nearly a century ago--"Criminals are made, not born"--to the Mein Kampf-sized manifesto of Norwegian mass killer Anders Breivik, whose dissertation goose-steps along for nearly a million words.