right next door to a huge shopping center in SoCal is the old tustin USMC air base, I read from a guy that snuck in to do some photography in the hangars, and he found simunition casings *everywhere*. You can bet your bottom dollar that police, military, etc train in these places all the time.

Heck, in FRANCE the army trains all the time in the villages as civilians go about their business, casually stepping aside to let the troops do their thing (obviously not with live ammo, but rifles, LMG's, etc).