and permanently silenced by CIA sharpshooters staged on the roofs of two opposing buildings. BTW, where they clearly could see that rooftop before any shooting took place and could have easily taken out the shooter at the mere sight of the rifle, but didn't? Another good question.

Not really that hard to figure out. Security at these things is handled by several layers of law enforcement. There are local cops, often handling things like traffic control and perimeter crowd control, there are state cops doing whatever they do. There’s Secret Service, FBI and other state and federal agencies involved, politicians or other dignitaries with their own security details, local EMS and similar - it’s not like every person there knows what ever other person is doing. They see a guy on a roof, even with a rifle, they probably asssume it’s a law enforcement sniper maybe.

I’m not complaining that it’s chaos, but every venue is different, it’s always a “once-and-done” and on to the next, with different people, different local officials, and do it all over again. I cut them a bit of slack for not instantly recognizing that this is a bad guy with a gun instead of a good guy with a gun.

That’s the funny thing. It’s hard to tell, sometimes. I see a guy walking thru WalMart with an AR-15 strapped to his back. How do I know?