Detecting the Patterns of Terrorist Attacks

Editor’s Note: This piece was published just five hours prior to the April 15 attacks at the Boston Marathon, a sad reminder of the continuous threat to the nation and importance of an improved understanding of how terrorist groups and individuals operate.

Does terrorism spread like a contagion? Or does hierarchal decision-making play a larger role?

personWith terrorism still a global concern more than a decade after 9/11, Piyusha Singh, PhD, a researcher with a background in criminology and public policy, shared a study on the patterns of terrorist attacks that could prove helpful to law enforcement officials.

Throughout her career, Dr. Singh, program director, Master of Science in Criminal Justice, at Excelsior College, has researched the context in which crime occurs, examining individual interactions to understand why violence escalates, and looking at how the physical and social environment affects the ability of police to improve crime prevention outcomes.

Prior to joining Excelsior College, Singh and a team of researchers (Gary Lafree, Laura Dugan, and Min Xie) from the National Consortium for the Study of Terrorism and Responses to Terrorism (START) and SUNY-Albany studied geospatial patterns in terrorist incidents. Their purpose was to gain a better understanding of terrorism by focusing on one aspect – when there is a decision made by leadership of terrorist organization, do we see a shift in their operations?

The team of researchers examined terrorist attacks by the Spanish terrorist group Euskadi Ta Askatasuna (ETA) between 1970 and 2007. ETA’s objective was to gain independence for the Basque region in Spain. In 1978, ETA publicly announced a strategy shift. Instead of limiting attacks to the Basque territory, the group would shift attacks outward across Spain in order to exhaust government resources and secure more recognition for their cause.

Singh and her colleagues noted this was a shift in strategy from “control,” where the focus is on protecting an operational base, maintaining a minimum level of internal security, controlling the population they intend to rule to “attrition.” In this latter phase, terrorist groups focus on increasing their influence through increased visibility, wearing down the opposing state and earning broader support for their cause.

“From a policy perspective, this information is useful to see whether theories predict changes in behavior, and we wanted specifically to see if a change in strategy produces a shift in geospatial patterns,” Singh said.

In order to examine this shift in strategy, the researchers examined patterns of spatial diffusion over time.

“We mapped the location of terrorist incidents to provinces and looked at changes in levels and examined whether changes in a province could be attributed changes in nearby areas or not,” Singh explained. “Contagious diffusion refers to the spread of phenomena, in this case terrorism to nearby units because of proximity. Hierarchical diffusion refers to a spread that is not due to direct contact between units.”

The researchers theorized that an increase or decrease in incidents within neighboring provinces was evidence for contagious diffusion (i.e., terrorism is spreading to nearby areas). On the other hand, if there were increases and decreases in a province that seem to be unrelated to changes in nearby areas, it would indicate that hierarchical diffusion is more likely.

They also argued that contagious diffusion would be consistent with control driven strategies by ETA, whereas hierarchical diffusion would suggest a strategy of attrition.

As predicted, when ETA switched from a control to attrition, the spatial patterns showed a similar change – from contagious diffusion to hierarchical diffusion. With this information in mind, Singh and her fellow researchers hope law enforcement officials can better understand the results of shifts in terrorism strategies.