Lone Offender: A Study of Lone Offender Terrorism in the United States (1972-2015)

This study from the National Center for the Analysis of Violent Crime/Behavioral Assessment Unit reviewed 52 lone offender terrorist attacks within the United States between 1972 and 2015, including 12 attacks related to racially-motivated violent extremism. The study compared numerous offender motivational factors encompassing their backgrounds, family and social networks, behavioral characteristics, radicalization, attack planning, and bystander observations. Predicting lone offender terrorism incidents is difficult, but prior research and operational experience support the conclusion that acts of targeted violence, including lone offender terrorist attacks, may be preventable through early recognition and reporting of concerning behavior. The report aims to inform broader goals of enhancing bystander education and awareness, as well to aid the prevention efforts of law enforcement and multi-disciplinary threat assessment teams working to counter targeted violence threats every day. To work toward this objective, the authors examine relevant contextual factors and analyze the statements and behaviors offenders exhibited before carrying out their attacks.