Oh right, so the dozen armed guys down the back who draw their weapons when they hear gun fire are going to go check the CCTV to find out who the bad guy is.
Or maybe they're instinctively going to know what sort of weapon he has by the sound of the first shot,,,
... and obviously they'll just know by default that there is only one attacker.
One thing for sure is they're certainly not just going to start blasting the first guy they see holding a gun!
Gottcha....
Yeah, because I imagine the bloke walking round executing people with a 'long gun' will look just like all the rest of em.