So I have been wondering how a 20 year old kid found a roof top were he could have a direct sight line to the podium. Was he on the crew that set up the stage and noticed that the rooftop was there? He would have had to have had knowledge of the layout of the venue. He would have had to have known how and where the stands would be placed. A shooter just doesn't happen to pick the right building and have a perfect shot without planning. No way he did that on his own. No way he just got lucky and picked the right spot.