He would have to be really really good.
As demonstrated by Flight 93, Americans will fight back and, specially in a roomful of soldiers, I can't believe that no one rushed him or tried to.
He would have to be really really good.
Not neccessarily.
I haven’t seen anything specific (other than it was in a building) but with the casualties as high as they are I am supposing this happened in a very crowded area.
A person opens fire with a semi-auto pistol in a crowd and before anyone can do much more than flinch and maybe duck down the shooter can have the first clip empty and be reloading or switching to a second weapon.