I was thinking about my post below concerning "crazies with guns." Do you suppose our society's manifest lack of interest in treating or taking care of people with mental illness actually causes some of these outbreaks of deadly violence?
I can imagine someone suffering from delusions, massive anxiety, insomnia, and fears of persecution being highly resentful of a society which by its indifference, seems to say, "It's your problem, buddy. We're not interested, you take care of it."
These outbreaks of shooting can be a way of getting attention, or more likely, the "9 mm attention" of an officer's weapon - so-called "suicide by cop."
