SOON AFTER THE school year started in September 2000, a police officer working at McNary High in Keizer, Oregon, got a tip about a junior named Erik Ayala. The 16-year-old had told another student that "he was mad at 'preps' and was going to bring a gun in." Ayala struck the officer as quiet, depressed. He confided that "he was not happy with school or with himself" but insisted he had no intention of hurting others. Two months later, Ayala tried to kill himself by swallowing a fistful of Aleve tablets. He was admitted to a private mental health facility in Portland, where he was diagnosed with "numerous mental disorders," according to the police officer's report.