A police dog at the White House Correspondents Dinner appeared to have gotten a sniff of the would-be assassin – but was pulled away seconds before Saturday’s shooting, new security footage shows. The video released by the Justice Department Thursday shows a handler leading a security dog toward the door to a stairwell that alleged shooter Cole Allen would use to try to access the White House Correspondents Dinner armed with a shotgun, knives and other guns. The dog lingers at the doorway for about three seconds, then walks away after getting an apparent tug from its handler. It then pauses and goes back inside the doorway. The footage does not include sound. Security footage released by the Justice Department shows a security dog showing interest in a stairwell door seconds before the alleged shooter burst through. U.S. Attorney Jeanine Pirro Immediately after the dog and its handler walk away, Allen is seen sprinting though the doorway and through a nearby metal detector, shotgun in hand.…