Ok I see this is a difficult notion to grasp so let me try explain this as well as I can. You said:
"I believe that school shootings would disappear if everyone knew that each school had two or three teachers (or administrators) who were armed and considered dangerous (to the bad guys), and willing to defend the defenseless. Guns are not the problem. People are. "
Getting some armed 'teachers' would be a great idea....if you think in a short-sighted way. How are you going to get pure and moralistic teachers who are well-trained in the art of firearm self defence? I think you can see the problem now. If people are the problem, then why are you suggesting they give more guns out to more people? One would think if you're into giving teachers guns, you aren't into lowering gun violence. You only want to fight fire with fire, and how useful is that statistically? Not good at all. Why you would want your child in a classroom with a teacher who is carrying a gun? If you could recruit Moses and Jesus and John the Baptist then fine you can trust human nature and firearms. Until then, mortals need less guns, contrary to what you seem to be saying. And it was a stolen gun. Why couldn't someone steal the teacher's gun?
"So, what do I want to see? Glad you asked. I would enforce present laws and keep felons in prison"..sounds like a campaign spiel reflecting the status quo. Kind of like a soup made from the shadow of a crow which had starved to death.
"I would also like to see more guns in the hands of honest citizens!"...and the grim reaper's smile shows his shiny fangs. And an exclamation point? You really love guns I take it.

Sorry to break it to you but if this kid couldn't get his had on a gun, he would have found another means. Building a bomb is very easy. Knives are effective. I don't know about you but I see commercials for swords on TV all the time. You have your pick, Conan's, Zena, or any other tv character. I'm not sure what the legal status of fireworks is in Minn or surrounding states but even if they are illegal, I'm sure someone can get them if they so choose. How hard is it to buy enough gunpowder to make a pipe bomb? My point is, just because this kid, who obviously had major mental problems, decided to use a gun to commit these murders, has nothing to do with the gun itself. Heck, I read an article in a newspaper a couple of moths ago where an individual killed 3 people with a stak knife. Do we make steak knife's illegal?? Of course not, that would be absurd!! Do we make fireworks illegal (in the states they are legal) because there is a possibility someone can make a bomb out of them?? O course not!! So why do people blame the gun when there is a tragety like this? Guns, by themselves, are a piece of steel, period. And in this case you can't even use the argument of personal ownership. The murder's grandfather was a police officer. He had to have a gun in his house, it was a job requirement.

The blame of this tragedy can only be put on one persons head, the boy. Obviously there was something seriously wrong with him Something snapped.
I don't think his infactuation with the nazi's was a factor. This kid was a loner because he was shut out by others. He was on antidepressants for some reason. Most likely it was the fact that his dad commited suicide or his mother is in a coma in a hospital. For a kid his age, he had alot going against him. But I have a question, with all of this going on in this boy's head, why didn't anyone see the many red flags (there had to be a few) go up?? People in a situation don't do this without a cry for help first. It might have been to his grandparents, friends, teachers, people he didn't like because of the way they treated him???

I think it's time to stop blaming guns for tragedies like this. Obviously there was some sort of breakdown in this kids life that no one picked up on. Let's focus on the why and not the how. If we can do that, maybe we can prevent future killings of this nature.

"Liberals booted God from the schools: no prayer, no Bible reading, no Ten Commandments, no teaching based upon the Bible. No speaking of Christ. After all, kids might really take those teachings to heart. They may decide not to lie, steal, fornicate, rape, and kill! They might honor and obey their parents, the law, and school officials. They might become kind, gracious, fair, honest, and principled! Heavens, we can’t have that can we? After all, we demand a secular society. Well, we have it and our schools have become Ignorance Factories, sex clinics, self-esteem laboratories, and sports clubs."

I suppose the good doctor would be completely helpless trying to figure out right from wrong if it wasn't for religion. I can only imagine the trouble things not specifically covered by a commandment must give him.

"All sane, sensible people would agree that fewer deaths would be preferable, but no one says the gun-grabbers are sane, sensible people. At least, I don’t. They are fallacious, frivolous, fruity, foggy, fluttery, flushed, flimflamming, flagellating, feverish, frightful, fanatical, frenzied, fraudulent, foolish fascists. For those educated in public schools, I am saying that gun-grabbers are fools."

It's so refreshing to see a pro-gun argument that contains a broad generalization accompanied by a long, incoherent stream of alliteration that I can only assume is an attempt to show us how educated the doctor is. Wait, did I say refreshing? I meant played out.

"His book, ISLAM: America's Trojan Horse! was published last year"

Huh. The exclamation point really adds alot to that, doesn't it? Anyways, its good to see another educated person that thinks Islam is terrorism. I'm sure his next book will be about how Catholics support child molestation and murdering gays.