FACT: The solution to mass shootings, literally is… more guns.

An active shooter is going to seek a soft target (gun free zone).
Gun free zones are what allow these tragedies to occur.
Immediately after a shooting is commenced you have an equation.
(1 armed and crazy) + (100’s unarmed, and not prepared)
A phone call is made, “bring a guy with a gun, to deal w/gunman!”
The more guns that arrive to the scene, the faster the shooter is neutralized.
Ergo, get the more guns there first. An ounce of prevention.

Your thought experiment about gun regulation is magical-thinking. Do you think if we banned all smoking paraphernalia in this country everyone would stop getting high? Would you be willing to bet your life on it? Murder is already illegal. So someone willing to commit an act of terror isn't going to be stymied by the law. Even if you could magically make people respect the law, people can lawfully make their own guns via printing and milling. They don't even need to register, or seek a permit (or permission).

If someone is hell bent on killing a bunch of random soft targets, then the single and only solution is to create an environment whereby more people are hard to kill. It's not ideal that anyone should have to defend themselves to the death, but this is the jungle. It might be made of concrete, maybe you can take the city out of the jungle, but you can't take the jungle out of the city. History has proven that there is a criminal element that persists despite the thin veneer of safety that civilization attempts to provide. Rape happens, murder happens, robbery happens, kidnapping happens.

I wish the news would focus less on making mass shooters celebrities, and provide more of a spotlight to idiots that get slain while attempting to commit a crime. Also if every time a gunman shoots up a school, the school is demolished, that kind of bullshit is only going to serve to motivate more crazy people to snap. Just imagine an unstable mind, who hates school, and everyone who attends it. A person who hates the world, and themself. Then they start noticing that every time there is a mass shooting, the school is demolished.

In their mind, they would probably love to be the person responsible for destroying the symbol of what they hate. We're collectively making too many bad decisions in these areas, we need to do smart fixes. Everything has been bassackwards for the longest time. Hopefully Trump will implement some realistic fixes that address the problem in smart ways. Enough of the magical-thinking, we need to get real!