A year after the massacre, an analysis by officials at the U.S. Secret Service of 37 premeditated school shootings found that bullying, which some of the shooters described "in terms that approached torment", played the major role in more than two-thirds of the attacks. A similar theory was expounded by Brooks Brown in his book on the massacre, "No Easy Answers"; he noted that teachers commonly ignored bullying and that whenever Harris and Klebold were bullied by the jocks at CHS, they would make statements such as: "Don't worry, man. It happens all the time!"