So with that, I go back to saying I'll go to a class to keep my guns or more intense background checks (using this as an example for possibly deterents). I do it for my job due to where I work (which also intensifies my belief in gun ownership) so I don't have a problem doing so every so often. A massacre can occur too if that same kid got in a semi and drove it down a crowded sidewalk. Opportunities are all around for this kind of person which they would take advantage of.
More intense background checks are absolutely necessary.
But there is still one kicker - None of you need an assault rifle.