 This video shows the gunman up on that nearby rooftop we're talking about. The FBI has now identified the shooter as Thomas Matthew Crooks of Bethel Park, Pennsylvania. That's just about a 45-minute drive from where we are right now. The shooter was up on that roof, we're told, for a very short time before he fired that weapon. The 20-year-old Shannon was a registered Republican, according to state voting records.