Consider two scenarios:

1. An armed madman comes to a place and starts shooting people. None of the people who's around is armed.

2. An armed madman comes to a place and starts shooting people. Several (say, five) people in the vicinity are armed.

Which madman is more likely to be stopped quicker — the one who outguns everyone else 1-0, or the one who is outgunned 5-1?

If this weren't a madman but Jack Bauer — or even an average highly trained soldier — the five may well be unable to stop the one. But otherwise, the odds would seem to be more against the madman in situation 2 rather than 1, no?

No-one can prove anything, of course. Maybe the five would be the first to be shot. Maybe they'd run away. Maybe they wouldn't be around. Maybe they'd shoot and miss. Still, if you had to bet, which would you bet would be the worse scenario for the madman, and the better one for his victims?

Now of course if arming the five people for the extremely rare situation when they'll need to stop a madman will end up causing more harm than good in the much more common situations when there's no madman around, that might be a bad tradeoff. That is the argument I've heard against letting students possess weapons on-campus: They're young, they drink a lot, they'll start shooting when they get into a hot argument in class or at a debate. I'm not sure that's right, but let's say it is.

What, though, is the argument against allowing professors and other university staff to possess weapons, if they choose? (Assume the professors lack criminal records, and assume they go through whatever testing and modest training is required to get a concealed carry permit, or perhaps even some extra training.) One argument is that it's just dangerous for law-abiding citizens to have weapons, because they'll start shooting over arguments or fender-benders. But that's precisely the argument that has been rejected by the 38 states that allow any law-abiding citizen to get a concealed carry license (or, in 2 of the 38 states, to carry without a license). What's more, as I understand it, people who get such licenses have in fact almost never committed unjustified homicide or attempted homicide (or even lesser crimes) using their guns. Whatever the pluses or minuses of shall-issue, the "licenseholders will start shootouts over petty slights" theory has not been borne out.

If Virginia and other states have found that it's safe to let law-abiding citizens carry guns on streets, in shopping districts, in parks, and the like, why wouldn't it be equally safe to let law-abiding professors and staff to carry guns in the university? What magic is there about a university that makes guns in law-abiding citizens' hands (again, let's even set aside college students, if we think they are unusually likely to behave foolishly) more dangerous at a university than elsewhere? I know there are some university professors who are, er, a bit odd. But wouldn't the average professor — or average university employee generally — who wants a concealed-carry license to carry on campus be at least as responsible as the average citizen who wants a concealed carry license to carry outside campus? Given that licensees don't start shootouts over fender-benders, and that gun store employees, police officers eating lunch, and other law-abiding people who are routinely armed don't start shootouts over arguments, why should we think that armed professors (to be precise, that small group of professors who chooses to get concealed carry licensees) would start shootouts at faculty meetings?

What then is the downside? One possibility is that if mad killers know that professors and staff may be armed but students won't be, the killers will shoot the professors first. It's hard to see why this would increase the total death toll, though, especially in cases such as this one. I doubt that the typical mad killer who's willing to shoot any university employees he comes across just in case they have guns would have spared them, and just shot a selected subset of unarmed students (and staff and faculty), if he assumed the employees were unarmed. And in any event, it seems to me that this modest risk is worth running, just as the risk that armed security guards would be shot first is worth running in order to provide the protection that armed security guards might offer.

Another possibility is that the mad killers would just start shooting lots of people very quickly, rather than at the relatively leisurely pace that we've seen in many mass killings. "I was going to walk around killing people over 15 minutes or half an hour," the killer might think (Kleck's Targeting Guns reports two mass killings that happened over 2-4 minutes, but seven that happened over 10 minutes or longer, including five that took 30 minutes or longer) — "but since there's now a substantial chance that I'll be stopped, I'll just shoot as many as I can as quickly as I can." But this strikes me as pretty unlikely; the pace of killings seems to be driven more by the killer's own mad desires rather than by a calculation such as this one.

Another concern might be that the universities would be held liable for their employees' misuse of guns. But, first, I take it universities already have liability insurance policies for possible misuse of weapons by university police officers. The employees who get concealed-carry permits (likely a small fraction of all employees, given that in shall-issue states the general pattern is that only a small fraction of all citizens get licenses to carry) could be added to such policies.

Given the pattern of safe use of guns by shall-issue licensees, I suspect insurance companies won't demand vastly higher premiums from universities for this. And the university could require some extra screening, testing, and training just to make sure that employees who get permits are as reliable as possible. Recall that many armed security guards are trained and screened only modestly, and they are likely to use their weapons more often (since they tend to guard places during high-crime times of day, and are more likely to be called over to the scene of developing crimes, which other armed university employees would rarely have to do). And if one thinks my analysis above is correct, and carrying by employees is pretty safe, but the liability system is unlikely to reflect this sound analysis, then some statutory liability limit — perhaps simply providing that professors and staff are armed on their own behalf, and the university thus wouldn't be liable for their actions — may be sensible.

I've also heard some arguments that suggest universities are different because they are places for reasoning, not violence: They should be gun-free zones (except of course for university police officers and security guards, who for some reason don't count) because that's needed to create the proper climate of peaceful inquiry. But the sad fact is that you can't make a university into a gun-free zone. Mad killers can bring guns, and use them, regardless of what policies you announce. The question is whether they will be able to use them against a disarmed population, or against a partly armed population. Allowing people the tools to defend themselves against the mad killers does not, it seems to me, worsen the climate.

[UPDATE: Finally, to give an even more essentialist version of the argument that universities are somehow unsuitable places for professors to be armed, let me quote a commenter: "There are a million reasons, but one will suffice for now. Schools and guns do not mix. Period. The more guns we inject into a school environment the worse it is for all involved...." It's hard to figure out how to deal with the argument that "Schools [including universities] and guns do not mix. Period." The commenter also mentions that professors "aren't trained for it, and I doubt they would be very good at it," but 38 states have taken the view that all law-abiding adults should be free to get a license to carry concealed weapons, and haven't had serious problems from the concealed-carry holders; the question is why those problems would suddenly appear at universities.]

Again, I should stress that this is not supposed to be a panacea, some guarantee that mad university killers will be immediately stopped. And I should say, as I've noted before, that there may be little point in planning for fortunately very rare events such as this one, which account for a tiny fraction of all homicides in the country. (The yearly average is that mass killings account for less than 0.1% of all U.S. homicides.)

But if we are trying to think what could have decreased the carnage, I've come around to the tentative view that allowing at least university employees to be armed is the likeliest solution. When one person — a not very well-trained person — comes into a place occupied by thousands of people, and kills over thirty, there's a simple explanation for why he could get away with it: Though he was outnumbered, they were outgunned.

If all university professors (and other employees) could be armed, and therefore some would be armed (again, I'm not saying that everyone will be armed, much less will be required to be armed, but only that some will exercise their right to get a concealed carry license allowing carry on campus), he would be both outnumbered and outgunned. Why wouldn't there be a very good chance that they would therefore be able to stop him earlier than he would have stopped otherwise?