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Terrorists act locally

New analysis of ATS reveals where terrorists live can help predict target locations

Like traditional criminals, most terrorists in the United States act locally, with more than a third of terrorists having lived within 30 miles of their target location and nearly half conducting relevant pre-incident activities within the same radius, according to an analysis of the American Terrorism Study (ATS) database funded through the National Consortium for the Study of Terrorism and Responses to Terrorism (START).

The database includes detailed information about 521 terrorist incidents from 1972 through 2011 -- both planned and carried out -- that resulted in federal court cases. In the more than 250 incidents with precise location data, the START research team -- Brent Smith, Paxton Roberts and Kelly Damphousse -- found that in most cases the residential locations of terrorists seem to have predictive value for both the locations of terrorists' antecedent activities (precursor or pre-incident activities) and their eventual target locations.

Al-Qaida-related terrorists committed more than two-thirds of their antecedent behaviors within 30 miles of where they lived, whereas environmental terrorists committed only about a quarter of their antecedent behaviors within 30 miles where they lived.

When contrasted with incident locations, the reverse is true: only about a third of the antecedent activities of al-Qaida-related terrorists occurred within 30 miles of the incident location, while nearly two-thirds of environmental terrorists' antecedent activities occurred within this range. Across all of the cases examined in the project, a more general pattern emerges. Terrorists appear to keep more distance between their place of residence and the operational behaviors most closely tied to their plot.

Fifty-seven percent of antecedent activities that were not directly related to preparing for an incident occurred within 30 miles of their residences, while 40 percent of preparatory activities and 35 percent of incidents occurred within the 30 mile radius.

"Unlike traditional crime, terrorism typically involves a number of preparatory acts and precursor crimes," Smith said.

"This difference between traditional crime and terrorism provides the best opportunity for law enforcement to intervene early. Data from the ATS can be used to identify patterns of precursor conduct that may give law enforcement the edge they need to counter terrorism."

The ATS database includes more than 4,000 spatial and nearly 3,000 temporal measurements. Further analysis of the database can be found in the report, "Update on Geospatial Patterns of Precursor Behavior among Terrorists." The report is part of a series sponsored by the Human Factors/Behavioral Sciences Division, Science and Technology Directorate, U.S. Department of Homeland Security, in support of the Prevent/Deter program.

The goal of this program is to sponsor research that will aid the intelligence and law enforcement communities in identifying potential terrorist threats and support policymakers in developing prevention efforts.

"Terrorism is limited by time and space," Smith said.

"Our next step in refining the relationship between time and space involves conducting 'crime-specific' analyses of the temporal sequencing of precursor behaviors. We have evidence that these precursor activities occur in a generally predictable sequence, further delineated by a specified temporal range. This may prove to be especially valuable to intelligence analysts and local law enforcement."

Smith is the director of the Terrorism Research Center in Fulbright College and a professor at the University of Arkansas. Roberts is a research associate at the Terrorism Research Center in Fulbright College (TRC) at the University of Arkansas. Damphousse is associate dean of the College of Arts & Sciences at the University of Oklahoma where he is also the President's Associates Presidential Professor in Sociology.

To download a PDF of the report, "Geospatial Patterns of Precursor Behavior among Terrorists," visit /start/publications/GeospatialPatternsofPrecursorBehaviorAmongTerrorists_Nov2012Update.pdf.