Unlike the butchery that bookended it, it merited no presidential statements, no saturation television coverage. But what took place at 6101 Prentice Street on Aug. 21 may say more about the nature of gun violence in the United States than any of those far more famous rampages. It is a snapshot of a different sort of mass violence — one that erupts with such anesthetic regularity that it is rendered almost invisible, except to the mostly black victims, survivors and attackers (...) “Clearly, if it’s black-on-black, we don’t get the same attention because most people don’t identify with that. Most...