America’s escalating epidemic of gun violence is detrimental to the mental health of millions of Americans. But experts say that Black people, in particular, tend to deal with a specific kind of despair with regard to mass shootings. This country’s latest incident of targeted violence is emblematic of that crisis. On Saturday, a white gunman shot and killed three Black people at a Dollar General store in Jacksonville, Florida, an attack that officials have charged as a hate crime. The shooter intentionally targeted Black shoppers, after first stopping at Edward Waters University, a historically Black university, where he was spotted...