Abstract
A common finding in criminology concerns the influential role of peers for offending. Even so, there is minimal literature, even at the descriptive level, on the extent to which the presence of co-offenders facilitates crime, especially violence. Within a ‘collective behaviour’ framework, we hypothesise that the presence of more accomplices (i.e., larger groups) will be related to an increased likelihood of violent crime. By reviewing data on both co-offenders and co-offending incidents, we find that: (1) violent offences have a higher average number of offenders per event compared to nonviolent offences; (2) as the average number of individuals with whom a person offends increases so too does the count of violent co-offences and (3) the odds of an individual's first group offence being violent increases for every additional accomplice present during the event, independent of whether these co-offenders had a history of prior violence. The conclusion advocates for more research on mechanisms of collective behaviour, paying particular attention to future theoretical and empirical directions.
