Visualizing the relationship among indicators for lone actor terrorist attacks: Multidimensional scaling and the...

Area of Science:

• Forensic Psychology
• Criminology
• Behavioral Science

Background:

• Assessing lone actor terrorists is crucial for national security.
• Understanding pre-offense behaviors aids in threat assessment.
• The Terrorist Radicalization Assessment Protocol (TRAP-18) is a structured professional judgment instrument.

Purpose of the Study:

• To validate the Terrorist Radicalization Assessment Protocol (TRAP-18) using a multivariate statistical approach.
• To examine the co-occurrence of risk factors in North American terrorist attackers versus non-attackers.
• To provide empirical support for the rational-theoretical model of the TRAP-18.

Main Methods:

• Analysis of data from 33 North American terrorist attackers and 23 non-attackers.
• Utilized multidimensional scaling (MDS) to visualize risk factor clustering.
• Focused on the eight proximal warning behaviors and distal characteristics outlined in the TRAP-18.

Main Results:

• Multidimensional scaling revealed significant clustering and co-occurrence of proximal warning behaviors among attackers, but not non-attackers.
• Distal characteristics showed less clustering and were present in both groups.
• The findings empirically support the TRAP-18's rational-theoretical model.

Conclusions:

• The study validates the TRAP-18's utility in identifying patterns of behavior associated with lone actor terrorists.
• The findings enhance quantitative analysis of observable indicators for law enforcement and counterterrorism.
• Recommendations are provided for operational use and future research on pre-offense behaviors.