School Gunman Had AR-15-style Weapon, 600 Rounds of AmmoSchool Gunman Had AR-15-style Weapon, 600 Rounds of AmmoA 19-year-old who killed a teacher and a 15-year-old girl at a St. Louis high school was armed with an AR-15-style rifle and what appeared to be more than 600 rounds of ammunition.Associated PressAssociated Press