The school in Newtown. The Sikh temple in Wisconsin. The movie theater in Aurora. America’s angst over shootings in public places is growing, and for good reason. According to a study obtained by Yahoo News, rampages like the Washington Navy Yard and Los Angeles airport shootings have tripled in recent years. The report, written by the Advanced Law Enforcement Rapid Response Training (ALERRT) Center at Texas State University, will be published next week in the “FBI Law Enforcement Bulletin,” a training publication for criminal justice professionals. Researchers considered only active shootings in public settings where the primary motive appeared to...