AP Photo/The Chronicle-Tribune, Jeff Morehead In New York City, police mistakes get played out on a big stage. In September, the New York Police Department’s (NYPD) performance was caught on camera in crowded Times Square when two officers shot at an unarmed suspect, missed him, and hit two bystanders instead. The man had been lurching in and out of traffic, ignoring police commands to stop, and at one point pulled his hand out of his pants as if he had a gun, according to a report in The New York Times . It was the latest in the department’s two-year run of an unusually high number of unintentional shootings of innocents. Last August, police wounded nine bystanders while unloading 16 rounds at a suspect who’d just shot a co-worker on the street near the Empire State Building. In separate cases last year, cops wounded four other bystanders. Gun battles and shoot-don’t-shoot decisions can be appallingly hard for even experienced cops to handle well. Low light, suspects in motion, and...