Frederick S. Calhoun, PhD, oversaw a national workplace violence prevention program for a large federal agency. He earned his PhD from the University of Chicago. He was the lead researcher and principal architect in developing the threat assessment process used by the United States Marshals Service for analyzing risks to federal judicial officials. He also developed the service’s policies and procedures for conducting protective investigations and wrote the curriculum and led the training of deputy US Marshals Service threat investigators and their supervisors. He is the author of 12 books and teaches a periodic two-day seminar, "Managing Threats: Reducing the Risk of Violence," designed to train law enforcement officers, mental health professionals, and private security officials to identify, assess, and manage individuals of violent intent.