Couldn't potential situations with armed people everywhere go badly as well? What about people getting caught in cross-fire, when it turns into a shootout especially if the first retaliatory shots miss? I'm not sure more guns on the scene necessarily means greater safety for everyone else. Anyway, just a thought
It could. Especially in a darkened cinema. (It should be remembered that plenty of mass shooters also wear body armor of some kind, and if using a rifle they often use an ammo, unlike most handguns, that can punch through say a chair, or ricochet. While individual citizens have indeed stopped mass shooters in the past, some of those ended up being killed themselves in large part because they didn't take this into account.)
At the same time there's been some impressive body counts from mass murder in places like China because a knife is so silent that no one thinks to run, especially like one guy who went through a boarding school slitting sleeping student's throats one by one. The mass shooting of Israeli schools--which I consider a different case from school shootings in the USA for multiple reasons--was stopped by arming teachers, all with military experience, and the mass murderers just switched to suicide bombers. Our own most deadly mass murderers used explosives, including at the Bath school massacre which killed about 40 little kids and injured about as many more, and if Timothy McVey hadn't practically flashed a neon sign he was the Oklahoma City bomber, quite proud of himself, he could've gotten a chance to do it again. Making these explosives can be ridiculously easy as the components are highly useful in agriculture and industrial ways and would no doubt become the next big thing if the impossible task of confiscating all guns from civilians were to somehow happen.)
I'm glad I made the right call not to pull my own gun some pranksters (gods I hope they were teens) threw some fireworks into a store I was at right after a mass shooting elsewhere that caused instant panic, as if anyone else did and not seeing a shooter (because there wasn't one) but seeing me armed might've focused on me (this is unlikely, mind you, but sure to have caused me problems with the police wanting to question me at the very least).
However, it's unlikely in most cases. This is mainly because people in such places know who belongs and who doesn't. The church members aren't going to start shooting each other (at least not on accident though they might try to pass it off as such if they can't blame it on the would-be mass shooter). When a mass shooter entered the Virginia’s Appalachian Law School in 2002, guns weren't allowed in the school but in vehicles, and at least two went out to get their own guns and then rush back in, taking down the shooter because it was obvious who he was while they knew each other and everyone else was hiding or playing dead. Maybe the situation would've been even better if they hadn't had to run to their car first. (You might be tempted to point out Virginia Tech in which was so high not only because there were no guns, but police came and left while the shooter was still active, even if taking a break to do some other stuff!)
Charles Whitman who murdered his wife and then opened fired from a college tower was trained as a sniper IIRC (too lazy to look it up). In any case, being many decades ago and in Texas, many students had guns and fires suppressive fire at him. While they could not stop him given his superior rifle and training and strategic cover, they did pin him down and stymie his attempts to kill more (but he still managed to kill many). This literal minute man militia did not turn on each other, they focused on the sniper.
And my favorite...
Thief who tries to rob a gun shop is shot dead by those in the store.
www.snopes.com
NOTE: acknowledging that sometimes guns save lives and having certain people armed, both with concealed and with open weapons, might not be a bad thing (and I personally know of times they saved lives without even being fired, just present in the hands of someone being targeted by violence, and guns have other uses where there are wild animals and vermin) does not mean you have to sign up with the NRA and embrace their extremist views of the 2A, refuse any form of regulation on acquiring and keeping guns, or deny the CDC the chance to study gun violence (just as they study death by drowning, car accidents, etc), or say AR-15s should be legal to purchase. One can choose to reject both extremes, not be forced to pick one over the other.
And like you, I'm much more concerned with the culture of rage that seems to be overtaking the USA combined with the old glorification of gun violence which has been combated by many for years by people who still supported responsible firearms ownership but also didn't want to see killing glorified. (That said, killing in self-defense is not murder, nor should vigilantism and self-defense be conflated as the same thing.) I saw the recent Joker movie (because I was dragged to it) and found a group that cheered at every sociopathic act far more disturbing than the movie itself.
