Another reason it could not be staged is that it could have gone wrong, ending any plans immediately. Trump doesn't strike me as one to gamble like that. The shooter was nearly successful in the attempt.

Some details are coming out, such as the identity of the shooter. But only basic background information has been reported. I think it may come out that it was a maladjusted young man. There has been no mention of mental illness, but that's a possibility. The guy was local, so it's unlikely antifa-related.