Columbine High School Had Armed Guard During Massacre In 1999

But was wearing non-prescription sunglasses when he fired at Harris.

"Might Gardner have had a better chance of hitting Harris if he'd been wearing his glasses? When the two traded shots, 11 of the 13 people killed by Harris and Dylan Klebold were still alive.
"If his vision is 20/30, no big deal," said James Rouse, an attorney who represents six families. "If it's 20/300, what's he doing shooting a gun?"

It certainly ought to affect the conversation (or is it shouting match?) we're having now about the appropriate response to the Newtown massacre.

An armed guard might work if someone shows up who just happened to drive by a school with an arsenal of weapons and just snaps. Unfortunately these shootings are usually planned in advance. The shooters have time to pick a target, case the target learn the movement of an armed guard. And then attack
Also a good guy would not fire unless he had a clean shot so having a good guy on the scene with a gun would not garantee anyones safety.

to be in the right spot, at the right time, with a clear shot. In a surprise attack, the attackers have an initial advantage.

Timothy McVeigh virtually lived at gun shows.

Breeding grounds for domestic terrorism.

They didn't buy them directly. However, they couldn't have bought those three guns, and the fourth, if private sales were tightly regulated.

Glasses or not, it's pretty hard to hit a target at that range with a pistol.
It should be noted that at that time, police procedure was to secure the perimeter, and wait for SWAT teams to arrive to enter the building. Following that shooting, procedures have changed. Now, the standard tactic is to not wait for SWAT team, but to enter the building and engage the gunmen, even if out-numbered.
The SWAT Teams had a difficult time. No entire unit arrived on the scene, so the teams were formed ad hoc from several agencies, and had no time to plan. The building was huge, with a maze of corridors, and the teams had no floor plan of the school. The teams also had to deal with confusing and conflicting reports coming in; up to eight gunmen, a sniper on the roof, hostages being held, automatic weapons, and the gunmen wearing body armor. All were false, but slowed down the SWAT Teams as they searched the building room by room, and evacuated survivors and injured. Also, there were several live bombs the gunmen had left, and all the abandoned bookbags and backpacks had to be assumed to contain explosives. Not to mention fire alarms blaring, fire sprinklers running, standing water, smoke, and a gas leak. All in all, an extremely difficult situation.

Virginia Tech had its own police department...

And Fort Hood was a fucking military base, where just about everyone was armed.

Did that stop the spree shooters?

only MPs (Military Police) are allowed to be armed.

Manned by folks who are real hardasses when compared to civilian cops.

shit that has been proven to not work as solutions to problems they helped create.

around school campuses with a locked gate (decorative but difficult to scale or break through) such as wrought iron landscaped to give it a nice look instead of the look of a prison. Many schools already have chain link fences around certain areas.

Then have a building several hundred feet or at least as far away as permissible from the locked gate where people check in, are ID'd and searched. The school itself would have bullet proof windows and a double entry at all entrances with bullet proof glass and be able to be opened easily from the inside in case of an emergency by just pushing the bar on the door. Faculty and students will be instructed not to let people in themselves. The guards will do it either with a scan card given to the visitor which de-codes upon use and an alert to admin there is a visitor, are they expected, etc.? So the admin can greet the person and take them to the office.

This would be pretty effective and give students and teachers a sense of security witout feeling imprisoned. No system is cheap or 100% fool proof but this is the best thing I've come up with or heard proposed. Then the students aren't subjected to armed guards in the school, armed personnel who can have their guns stolen or used accidentally, etc.

It would be expensive, but then what are young people's lives worth?