Predictably, in the days following the Aurora, Colorado, tragedy, some gun enthusiasts have argued that if several theatergoers had been carrying concealed weapons that night, they could have limited the number of people killed and wounded. We heard the same suggestions after the Gabby Giffords shooting and after the Virginia Tech shooting.

It was good to read in this morning’s Times, then, the op-ed piece by Michael Black, a former Chicago police officer.

Black relates some of his own experience with armed criminals - and he emphasizes the difficulty that well-trained, experienced officers have when they’re faced with someone with a gun.

In the Aurora theater, with the sights and sounds of the movie combining with gunshots from a live person and a panicking crowd: “Even a highly trained armed police officer would have been caught off guard,” Black writes. “Try adding a bunch of untrained, armed civilians into the mix - this type of intervention could have made things much worse.”