WE DO NOT LIVE IN A COMIC-BOOK UNIVERSE.
There are no "Good Guys" or "Bad Guys"
....because humanity is an inherently flawed animal, and we are all, every one of us, capable of doing "Good" or "Evil" on any given day. This doesn't even begin to get into the argument of how one defines the twin concepts: someone else's "Evil" may well be your "Good."
There are no "Smart People" or "Stupid People"
... because all of us are capable of both on any given day, any given hour.
There are no "Sane People" or "Insane People"
... because "sanity" is never an absolute, and we all go crazy sometimes. I'd say my Dad was sane probably most of the time. But often enough, he wasn't. He'd probably still be alive today if there hadn't been a gun in his house.
Are the Police always "Good People"?
Hell, no. They gun down innocent people in the streets all the time.
THERE IS ONLY ONE SOLUTION
... and that is meaningful Gun Control, starting with a Complete Ban on the sale AND MANUFACTURE of assault rifles and all other weapons of capable of firing that number of bullets in rapid succession.
YOU DON'T NEED THEM FOR "HOME DEFENSE."
YOU DON'T NEED THEM FOR "HUNTING."
It is not a matter of so-called "good" or "evil." The tools of mass murder need to be taken off of the playing field. Banning their ownership is not good enough. Only a complete ban on their manufacture and sale will work at this point.