Jillian Peterson, PhD, has led large-scale research studies on mental illness and crime, school-shooting prevention, and mass violence, which have received national media attention. She is a professor of criminology and criminal justice at Hamline University and the faculty director of the Center for Justice and Law. She lives in Saint Paul, Minnesota. James Densley, PhD, is a professor of criminal justice and first University Scholar at Metropolitan State University, which is part of the Minnesota State system. He has quickly established himself as one of the world’s leading experts on street gangs and youth violence, including cyber violence. He lives in Saint Paul, Minnesota.