Despite your sarcasm, it's clear that what you are advocating is a violation of due process.
Okay..then as I stated...due process requires we decide (as a society) that something is bad, act to avoid it, and accept the law that does so...as a Society.
Helps us become a bit better...eventually.
I think we can agree that the slaughter of children en mass meets the criteria of "Bad".
Likely we can agree as well that a bad ass gun was involved.
Everything else beyond this issue involves a person....the obvious cause of this is the freakin' automatic weapon that was used to kill 20 children, and the nut job that used it.
One side accepts there was a nut job.
The other ignores the GoD Damn Gun.