Terrorist Networks and the Collective Criminal Career: The Relationship between Group Structure and Trajectories

Criminology theories have long pointed to criminal groups as playing key roles in shaping offending behaviour. While empirical research has refined this link, showing that individuals’ connectivity to criminal groups shapes their offending patterns, few studies have focused on the group as the main unit of analysis. We know little about the factors that lead criminal groups to emerge and even less about what leads them to evolve and persist over time. Focusing on group trajectories, this dissertation presents three studies that examine the evolution of the networks of terrorist organizations. Drawing from detailed network data derived from self-reports and official sources, this study examines the structural properties associated with 1) turning points in a group’s emergence and transition into violence; 2) network formation before and after a major law enforcement intervention; and 3) repeat offending across terrorist attacks. Collectively, findings showed how a group’s network structure is key for amplifying or attenuating their life cycle. However, group trajectories were found to depend not only on subgroups of densely connected offenders, but also leaders who played key roles in bridging the network and regenerating it over time. These results are used to conceptually develop a typology of group trajectories to explain variations in the life-cycles of terrorist organizations.