"Though, I'm sure that a uniformed Marine aiming a .45 at ones cranium and commanding said BG to drop his or her firearm might be more intimidating than a Police Officer or even a private citizen performing the same action."
Oh really, why would that be?
"I don't mean to offend anyone, but, it's known that a lot of cops can't shoot for crap, and the marksmanship of the average citizen may be questionable to the casual observer, but we all know what a Marine can do."
I was a marksmanship instructor for my company (Echo 2/6) when I was in the Corps, and shooting a rifle is alot different than shooting a handgun. The handgun course is ridicuously easy. Grunts handle and shoot their weapons often. Other MOS rarely shoot their carry weapons except for yearly quals.