 And the Trump supporters who went to his rally last night in Butler, Pennsylvania, had no idea that they were going to become witnesses to history. Some who were there were frustrated that they weren't listened to. In the days and weeks and months to come, many will ask how the shooter was able to get in a position to have a clear shot at former President Trump. This man says he told Secret Service agents that there was a man on the roof of a nearby building with a weapon.