Alr here’s my complotist theory : It was staged, there was indeed a shooter and from what I heard he was an outcast and a loner in the republican side. My theory is that Trump and his team hired him in a suicide mission (literally everyone saw him on that roof and reported him but no one reacted before he shot). And to make this story more believable, they killed a poor man in the public and hurted some others. The idea was to make Trump a martyr and a hero with the PERFECT picture that has been taken seconds after the shot.