On Megyn Kelly's show, yesterday there were a couple of professionals, one an ex-Secret Service agent, and the other one a sniper, discussing the events. Both opted for the SNAFU theory, especially the sniper.

They even said that it wouldn't be unthinkable, in a context of sheer incompetence by the local law enforcement in charge of the perimeter, that the cops in charge of securing the roof simply decided that it was way too hot that day to be outside and that was the reason why they were inside of the building instead. They also said that the whole thing was mainly due to lack of communication between agencies.

Which, to me, sounds all reasonable and whatnot. Except... how did the shooter know that the cops in charge of that specific building would do what they did? How did he simply walk by through the perimeter and climbed onto that roof unimpeded while carrying a gun? (The open carry state excuse just doesn't fly. They would have at least stopped to talk to him, and definitely prevented him from getting onto the roof. This is not even a real argument)

He obviously KNEW he would be able to get to the vantage point unimpeded.