It is tempting after such unspeakable crimes to search for answers that will help prevent a repeat. The media immediately examine the purported killer's profile and make sweeping statements about mental health screening, public health programs, bigotry, the schools and popular culture. Some correlations might deserve attention, such as the Wisconsin shooter's former military status, because the increased prevalence of traumatized military veterans is unavoidably a national issue.
Yet, for the most part, senseless acts of mass violence can never be explained in a way sufficient to stop the next attack.