I AGREE with you, right to carry would not NECESSARILY have stopped that attack, and even having armed persons is no guarantee. But I DO think that if a few of those types started getting popped at the beginning of their sprees it would have a chilling effect on the whole spree killing genre.
A key fact in each shooting is often unreported, or barely looked into.
Time from first shot to last shot by the maniac.
If it’s longer than one minute, then a citizen with a CCW could have stopped it.
Every murder past the one-minute mark should be chalked up to the killer finding a disarmed victim zone, like a wolf in a pen full of lambs.