School mass shooting is the biggest threat to the school safety and the public health, it somehow has become an American routine and rapidly increased since last thirty years. The School Shooting of Columbine, Sand Hook, and Virginia Tech have become the “icon” of American history because innocent children and students are killed in schools where they are supposed to be safe and to learn knowledge from. As the public, we condolence the dead and their families and condemn those offenders and their heinous crimes, but at the same time, researchers have begun seeking for what mass school shooting is and what characteristic, motive and risk factor are contributing to those mass school offenders. Meloy, Hempel, et, al (2004) defines that “Mass murder
