I don't really have an opinion one way or the other on a second shooter, except that it would make it make sense as to why there was no friendly security posted on the water tower.

I do not believe that they were incompetent enough to just not think to use the highest easily accessible point that gave them eyes on the entire event.

And "we didn't put someone on that roof because it was pitched (at like 8 degrees) and wasn't safe" ... as they had snipers on other roofs with steeper pitches ... that's just insultingly stupid. Nobody believes that (except perhaps the DEI idiot running the Secret Service).