Could janitors be one school's line of defense?

Yes, I'm still against arming any and all school personnel.

And, this is a particularly dumb idea...

...announcing to the public who will be carrying a handgun.

Now the perpetrator doesn't have to plan to get a gun into the school...

...the gun is already there, beyond the metal detectors.

Now, all he - (so far there have been no she's that I know of) - has to do is report to the office, spill his coffee, await the calling of the janitor to clean it up, overpower same...instant armed intruder. (Yes, the upside is that our armed intruder doesn't have a weapon of mass destruction, he can only kill a limited number of innocents. Hmmm...wonder how many magazines of ammo the custodian will be allowed to carry?)

But...

It gets worse!

Now students inside the school have daily access to a gun or guns. Whenever the evil spirit moves them, the students can gang up on the custodian(s), take his (their) gun(s), and commit their acts of violence.

I'm sorry, I'd rather take my chances on the odds...

...still pretty good that one will get through the school day without getting shot.