In light of the Paris and Mali attacks these last two weeks many armed citizens are preparing themselves to respond if the Bad Thing (upper case) happens on their watch. That’s not irrational. My friend Marcus Wynne, who has spent decades working for or with or around the world’s premier CT units has an insightful and useful guide to that effort here.
On the other hand, random violence is a far more likely scenario for most of us. Claude Werner, another friend in the shooting community, has a gift for detailed data analysis and distilling that data and its implications in a to-the-point way. His take on keeping perspective and focusing on preparing for the bad thing (lower case) is here.
Both are well worth the few minutes it takes to read. Well worth.