Bodycam footage shows the moment a police officer climbed to the roof of a building overlooking Donald Trump's rally and spotted the would-be assassin, Thomas Matthew Crooks, just before the shooting began. Additional footage shows local officers telling the Secret Service to post officers near the building days earlier due to security concerns. The bodycam video from the officer on the roof captures him dropping down in panic after making eye contact with Crooks 40 seconds before the shooting. Dashboard camera audio captures the shots fired by Crooks and officers shouting not to expose themselves and warning others that the shooter may come down from the roof.