Maryland News Mass Shootings In The U.S. July 22, 2012 / 6:36 PM EDT / CBS News GARY EDWARDS/AFP/Getty Images Mass Shootings In The U.S. LUKE FRAZZA/AFP/Getty Images Mass Shootings In The U.S. MARK LEFFINGWELL/AFP/Getty Images Mass Shootings In The U.S. Photo by Henry County Police Mass Shootings In The U.S. Photo by Darren Hauck/Getty Images Mass Shootings In The U.S. JEFF HAYNES/AFP/Getty Images Mass Shootings In The U.S. Photo by William Thomas Cain/Getty Images Mass Shootings In The U.S. TIM SLOAN/AFP/Getty Images Mass Shootings In The U.S. Photo by Eric Francis/Getty Images Mass Shootings In The U.S. Photo by Tasos Katopodis/Getty Images Mass Shootings In The U.S. Photo by Spencer Platt/Getty Images Mass Shootings In The U.S. JIM WATSON/AFP/Getty Images Mass Shootings In The U.S. Photo by John Moore/Getty Images Mass Shootings In The U.S. Photo by Kevork Djansezian/Getty Images Mass Shootings In The U.S. DON EMMERT/AFP/GettyImages
