I've heard some say that Zimmerman wouldn't have been performing neighborhood watch duties, if he hadn't been armed. Nonsense. A lot of people perform these duties without being armed. (I would also have carried a force alternative--baton, pepper spray, and a Surefire M6 Millennium tactical light.)
Also a visible weapon (open carry) might not discourage an individual intent upon closing and attacking security personnel. I am curious: Was Zimmerman's orange/red vest a neighborhood watch "uniform"?
He wasn’t on neighborhood watch that night. He was just driving home from somewhere.