Author Biography

Dr. Diane M. Zierhoffer is an operational psychologist contracting to the Department of Defense. She has an MS in Terrorism and Counterterrorism Studies from Henley-Putnam University and a Ph.D. in Counseling Psychology from Indiana State University.



Subject Area Keywords

Law enforcement, Psychology, Terrorism / counterterrorism, Threat assessment


This study evaluates the viability of a threat assessment model developed to calculate the risk of targeted violence as a predictor of violence by potential lone terrorists. There is no profile, to date, which would assist in the identification of a lone terrorist prior to an attack. The threat assessment model developed by Borum, Fein, Vossekuil, and Berglund and described in “Threat Assessment: Defining an approach for evaluating risk of targeted violence” (1999) poses ten questions about the patterns of thinking and behaviors that may precipitate an attack of targeted violence.

Three terrorists are studied to assess the model’s value as a predictor of terrorism. It is assessed for its use within law enforcement, during an investigation of someone brought to attention as a possible terrorist and for family members or friends who suspect potential terrorist behavior. Would these questions encourage someone to report a friend to prevent a possible attack?

This threat assessment model provides a foundation for future research focused on developing a structured risk assessment for lone terrorists. In its present form, the questions can assist both citizens and law enforcement personnel in identifying the patterns of thought and behavior potentially indicative of a lone terrorist.