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Pre-Incident Indicators of Terrorist Incidents: The Identification of Behavioral, Geographic, and Temporal Patterns of Preparatory Conduct

NCJ Number
Date Published
March 2006
539 pages

Building on previous study findings, this federally supported study explored whether sufficient data exists to examine the temporal and spatial relationships that existed in terrorist group planning, and if so, could patterns of routinized preparatory conduct be identified?


Findings examining the temporal and spatial distribution of terrorist group activities demonstrate the potential uses of geospatial methodologies using open source data on terrorism. Findings revealed a bimodal spatial distribution of terrorist planning and targeting. About one-half of the terrorists in the study resided, planned, and prepared for terrorism relatively close to their eventual target. One-fourth lived and planned their acts a distance of several hundred miles from the terrorist target. These two patterns reflect operational variations among terrorist groups. In relation to general temporal patterns of activity, on average the terrorist groups studied existed for some 1,205 days from the date of the first known planning meeting to the date of the actual/planned terrorist incident. Some groups operated for several years which was uncharacteristic for most terrorist groups. The planning process for specific acts began, on average, approximately 2 to 3 months prior to the commission of the terrorist incident. Approximately two and one-half known planning and preparatory behaviors were recorded per incident, which varied, by type of terrorist group. In focusing on the planning processes and behaviors that terrorists engaged in while preparing for terrorist incidents, this study supported by the U.S. Department of Justice, National Institute of Justice, examined selected terrorist groups/incidents in the United States from 1980 to 2002. In examining the precursor conduct of terrorist group members, it places the subsequent terrorist incident in context and provides for the potential to identify patterns of conduct that might lead to intervention prior to the commission of the actual terrorist incidents. The study focused specifically on temporal and geographic distribution of these terrorist behaviors. Figures, tables, references and appendixes

Date Published: March 1, 2006