As a veteran law enforcement officer (20 years) I have had the distinct displeasure of running into a convict after he was paroled from a 15 year sentence that I was partly responsible. Dirt bag remember exactly who I was. His last words to me before has was lead out of the court room were "I am going to @$@$ing kill you when I get out". MInd you, this was in a grocery store in a very nice suburb.
Never mind that bad people are everywhere, just not in the "bad" parts of town. I carry when I cache, heck I carry just about 24/7 when ever I am out of my house. As for citizens, the Second Amendment says it all!!!