Drone footage of the rally site shows the distance between the roof where the gunman fired at former president Donald Trump. Signs of trouble were evident in the minutes before shots rang out at Trump’s rally in Pennsylvania: Police had a report of a suspicious man pacing near the magnetometers and were apparently exchanging photos of the suspect. Witnesses pointed and shouted at an armed man on a nearby roof. When a police officer climbed up to the roof to investigate, the gunman turned and pointed his rifle at him. But the officer did not — or could not — fire a single shot. A sniper cut down 20-year-old Thomas Matthew Crooks within seconds of him firing an AR-style rifle toward the former president, but it was too late. Now investigators are trying to painstakingly piece together how an armed man with no military background managed to reach high ground and get the jump on teams of Secret Service agents.