The nation is gripped by the shocking crimes: "good kids" who are suddenly, inexplicably lethal, shooting their classmates before fatally turning their guns on themselves. When Connecticut mom Dr. Lexi Bradley gets the call that her son Juan has become one of those shooters, her life is turned upside down. Ten years ago, Secret Service agent Bryan Atwood became an expert on school violence. Now the nightmare is back. Just as he is assigned to this...