 We cannot allow for this to be happening. We cannot be like this. We cannot condone this. Greg Smith was attending the rally and tells BBC News. We're like, hey man, there's a guy on the roof with a rifle. And the police were like, huh, what? You know, like they didn't know what was going on. You know, we're like, hey, right here on the roof, we can see him from right here. We see him. Secret Service agents killed the suspect, 20-year-old Thomas Matthew Crooks, after he fired several shots.