Polarisation of adolescent offending trajectories during the youth crime decline: A multi-cohort analysis of justice-involved adolescents in Australia

Despite growing research on the youth crime decline, there has been limited analysis of how these trends have influenced offending in cohorts born after the mid-1990s. This study aimed to examine changes in offending trajectories among Australian adolescents with a proven offence aged 10 to 16 years across 12 consecutive birth cohorts (1995 to 2006), in Queensland, Australia. Findings indicate that the number of adolescents with a proven offence decreased by 44% from the oldest to the youngest cohort. However, within recent birth cohorts of justice-involved adolescents, there have been significant increases in high frequency and violent offending. Additionally, despite declines in offending participation, First Nations adolescents have become more over-represented in the youth justice system, due to steeper declines in offending participation for non-First Nations adolescents. Latent class growth analysis was used to identify offending trajectories across the birth cohorts. Multinomial logistic regression indicated that recent cohorts of justice-involved adolescents were significantly more likely to display moderate or chronic offending trajectories, compared to low-level offending. Findings suggest that while criminogenic risk has reduced across the majority of adolescents in recent birth cohorts, for a subset of adolescents it has also increased. Theoretical and policy implications are explored.