Officials investigating the shooting at the White House Correspondents' Dinner said they estimated the suspect was running at about 9 miles per hour when he sprinted through a checkpoint and discharged his shotgun. The alleged gunman was running at full speed as he raced past the magnetometers on the second floor of the Hilton hotel in Washington, D.C. He discharged his shotgun, likely hitting the cellphone tucked inside the pocket of the bulletproof vest worn ... [3785 chars]