Our latest mass shooting in Oregon - which did NOT occur in a gun-free zone - is just the latest reminder that good guys with guns, as good as their intentions might be, are oftentimes no match for bad guys with guns.

The insanity defense, which dates back to ancient times, is a controversial defense option. In fact, not all 50 states allow an insanity defense, and several of those that do have rejected "not guilty by reason of insanity" in favor of the less-forgiving "guilty but insane."