Americans have become accustomed to tragic headlines of mass shootings in schools, grocery stores and other public places – these shootings still shock, but they no longer surprise. Jillian Peterson, PhD, of Hamline University, talks about research on what drives most mass shooters, why thinking of mass shootings as suicides as well as homicides can suggest new ways to combat them, and what can be done in schools, workplaces and elsewhere to make the next mass shooting less likely.