Discussing the effect of guns on preventing or stopping crimes is a practice that inherently relies on anecdotal situations, real and fictional. Here's a real one for consideration that caught my attention.
I think everyone can reasonably agree that nothing that didn't remove Congresswoman Giffords from public contact could have prevented Jared Loughner from opening fire. It's the essential advantage of an assassin, that he gets the first shot because nobody knows he's there or that he's going to shoot somebody. So that's agreeable. It's what happened afterward that sort of spiraled into this gun debate, that among the various sides one is that if people at the event had been armed, including
Arizona Representative Trent Franks, it would not have prevented Loughner from opening fire but it would have... uh... resolved it in a more satisfying manner? In other words, there's this wistful notion out there that if responsible people around Loughner also had guns, they could have shot him down OK Corral style and minimized his attack.
In fact, there were people in the area who were armed and ready.
Joe Zamudio was inside Walgreens, exercising Arizona's right to carry a loaded pistol concealed in his pocket, when he heard the shooting and commotion outside the store. He ran out, hand on gun with the safety off. He saw people struggling, bodies on the ground, and a man holding a pistol. Being fairly close and thinking the man with the gun had not noticed him, Zamudio chose to tackle him instead. Afterwards, they were pulled apart, when the same people struggling convinced him the man holding the gun was not the shooter.
By Zamudio's own recollection, he was fully prepared to shoot the "gunman" but chose not to, and that if he has acted on his initial impression, he would have shot the wrong person.
The inherent problem with the idea that other people being makes them better able to subdue a crime in progress, is that anyone who didn't actually see the original attack doesn't know who the "bad guy" is. An armed Good Samaritan running onto the scene only knows that somebody is shooting, which means that
anybody he sees holding a gun is potentially the right target. If there's more than one person shooting, at each other even, now what? And just imagine the confusion when the police arrive. They know there have been people shot, they reach the scene and see people holding guns. The best possible outcome is that they arrest everybody involved, to be sorted out in court later. Even if nobody but the attacker is shot, when police respond to a round-robin shootout, they have no responsibility to take anybody's word for it on who the "real" criminal is. After Zamudio's confusion,
Cnl. Badger had the presence of mind to tell everyone to leave the gun on the ground for just that reason.
When you come packing heat the scene of a shooting, looking for the shooter, there's a few critical seconds where you have no idea who's dangerous and who's safe, and nobody else does either. Even assuming that responsible gun owners have laser-perfect accuracy (which, when trying to find a shooter in a panic screaming crowd of wounded people, is a big fucking assumption), the most personally-protective thing to assume is that anyone armed is the dangerous target, especially anyone who assumes you are. And the great thing about guns is, you only have to act on your well-intention but incorrect judgment for one second to ruin your life and probably somebody else's.
There's no real point here about any actual gun laws, but every time I hear
the argument that more responsible gun ownership would prevent crimes or keep them from escalating, I feel like it's underscored by the belief that responsible gun owners can take down the badguys in cinematic flair. Zamudio's own account of the shooting underscores that the most responsible decision he made was to not use his weapon, because he turned out to have the wrong man in his sights.
If you want to hear his comments yourself,
here's a YouTube host of the appearance. Ed Schultz is a blowhard of the highest caliber, but it's the only filmed interview Joe Zamudio gave, so that's what you have.