The date was January 12, 2013. You probably didn’t hear about this tragedy involving guns and two teenage boys. But this was the headline in the Chicago Tribune: “Boys, 14 and 15, killed in separate shootings Friday.” You didn’t hear about it because such events aren’t news in Chicago. They’re ordinary daily occurrences. As we continue to hear calls for ever-tightening gun laws from the Obama administration, and from states such as New York, it is worth thinking about those headlines in Chicago. And in inner cities all around America, places where strict gun laws are already in place. Places...