A life-course analysis of offense specialization across age: Introducing a new method for studying individual specialization over the life course

Much of the knowledge base on offense specialization indicates that, although there is some (short-term) specialization, it exists amidst much versatility in offending. Yet this general conclusion is drawn on studies using very different conceptualizations of specialization and emerges with data primarily through the first two to three decades of life. Using data on a sample of Dutch offenders through age 72 years, this article introduces and applies a new method for studying individual offender specialization over the life course. The results indicate that although, in general, individual offending patterns over the life course are diverse, there is also evidence of an age-diversity curve. Linking offense frequency trajectories to the estimated diversity index, the authors also examine distinct specialization patterns across unique trajectory groups. Implications for theory and research are outlined.