Examining co-offending and re-offending across crime categories using relational hyperevent models

Research on co-offending has become increasingly popular across the last two decades of criminological research. In this paper, we focus on three key variables and their relationship with co-offending. First, we examine age and sex homophily effects. Second, we examine the differential effects of prior solo offending and prior group offending on the future arrest rate (overall and separately for different crime categories). Third, we examine whether there are age and sex effects and age/sex homophily effects on arrest rates (overall and across crime categories) and on propensities to be arrested again in future. Results suggest that individuals who committed group crimes in the past are more versatile in future criminal activities. Market crimes appear to require the highest level of specialisation among the four types of crimes in the sense that those who committed market crimes in the past commit market crimes in future and tend not to commit subsequent novel types of crimes. Individuals who committed crimes other than market crimes in the past tend not to engage in market crimes in the future. When co-offending groups are more heterogeneous with respect to age or sex, the effect of past arrest on propensity for future arrest is stronger. We draw implications for policy and practice based on the results of the study.