Nine passers-by were also wounded, and it seems almost certain that some or all were accidentally hit by the police. This isn’t surprising; it’s only in movies that people are good shots during a violent encounter. In 2008, Al Baker reported in The Times that the accuracy rate for New York City officers firing in the line of duty was 34 percent. And these are people trained for this kind of crisis. The moral is that if a lunatic starts shooting, you will not be made safer if your fellow average citizens are carrying concealed weapons. This is not the accepted wisdom in many parts of the country. (Certainly not in Congress, where safety was cited as a rationale for letting vacationers take loaded pistols into federal parks.) Shortly after the mass murder at the movie theater in Colorado, I was waiting for a plane at a tiny airport in North Dakota, listening to a group of oil rig workers discuss how many lives would have been saved if only the other theater patrons had been armed. “They could have nipped it in the bud,” one man told another confidently. People, try to imagine what would have happened if, instead of diving for the floor, a bunch of those moviegoers had stood up and started shooting into the dark. Or ask a cop.