The 12-year-old who used 9mm semi-automatic Ruger handgun on Monday in a shooting at a Nevada middle school obtained his gun at his home. The student, whose name has not been released, shot two students and killed a teacher before shooting himself. The parents, who are cooperating with authorities, could face charges as well. No motive for the shooter has been found. "Everybody wants to know why — that's the big question," Sparks Deputy Police Chief Tom Miller said. "The answer is, we don't know right now."