Authorities say none of the injuries are life-threatening.
Karl Pierson intended to spread much more carnage in the attack at Arapaho High School, say authorities.
Police say a gunman walked into a Catholic church and shot a man in the back of the head during Mass on Sunday in Ogden.
All four people killed by a former neo-Nazi before he turned the gun on himself this month in a quiet Phoenix suburb were shot in the head, according to a police report released Tuesday that paints the clearest picture yet of the gruesome crime scene.
Police in the town where the Nevada gunman worked have confirmed he had a previous run-in with the law involving his mental health.