A sniper opened fire Saturday while Donald Trump was speaking at a campaign rally in Pennsylvania, hitting the former president’s ear, killing a bystander and seriously injuring two others, federal officials say. The suspect was shot dead by the Secret Service. The attack happened at 6:11 p.m. on Saturday, just minutes after Trump took the stage to address a rally at the Butler Farm Show Grounds near the small city of Butler, roughly 27 miles (43 kilometers) north of Pittsburgh. Officials said the gunman, who was later identified as 20-year-old Thomas Crooks from Bethel Park, Pennsylvania, use…