Don't ya love it when people present the products of their imagination as factual evidence and proceed to invent a new world where everything conforms to their opinion?
Yep. How many more kids have to die in their schools before the people opining for "prevention" realize there's only one measure that has a chance to work after all others fail?
Let's say 1,000 mass shooters are walking around in schools now. They won't all commit murder today. Some will tomorrow, some in a year or more, and some will "read a book" and decide not to kill.
Let's say 500 events are "prevented" through proper psych meds, religion, getting a girl friend, finding a great after school job, or counseling. That leaves another 500 kids planning and building up the desperation and hate to the point they finally take a gun to school and end their pain while making their mark on history.
That's 500 shootings that could happen over the next 1-5 years, and if we only focus on prevention, there won't be anyone at the schools the day of the event to stop the maniac.
There are preventatives for heart disease, like diet, exercise and medications. But tens of thousands who did everything right still get the disease. At that point, they need to TREAT the disease, because prevention failed. They need rehab, different medications, and possibly a transplant.
Even if we could reduce the number or patients to 1% what it is now, you still have to continue producing and researching ways to CURE the remaining 1%.
Why not invest the time and resources NOW in "treating" school shootings, because we know already with 100% certainty it will happen again and again. Without that, kids will die unnecessarily as those arguing against teachers carrying guns do absolutely nothing to stop them once they decide to kill.
No different that carrying a weapon for self-defense. When the gov't can take every single gun, knife or other weapon from all the criminals, then MAYBE I'll stop believing firearms carried outside the home is a necessity. Until then, it's MY CHOICE, not the government's, and not some gun control group's decision what I carry and how many rounds is "enough". My life, my family's life -- my choice. Same should apply to teachers and faculty. Give them the CHOICE to be prepared.