Binnie, I really think the issue is mental health. The problem here is that whenever one of these kooks rears their ugly heads, they usually kill themselves, thus not giving the scientific community a chance to study their brain dysfunction.

The trick is to capture one of these kooks, preferably before they kill, identify their illness, then screen for it in the general population.

Then...

adjust gun laws accordingly.

That translates to "anyone diagnosed with xyz condition is banned from owning or handling a firearm", period.

It's as simple as that.