 As one witness later described it, we noticed a guy crawling, you know, bear crawling up the roof of the building beside us, 50 feet from us. So we're standing there, you know, we're pointing at the guy crawling up on the roof. He had a rifle. We could clearly see him with a rifle. The Butler County Sheriff said that shortly before the shooting, an armed officer tried to reach the gunman but had to fall back.