Criminal justice transitions among adolescents in Australia: A multi-state model

This study aimed to identify key transitional pathways in the criminal justice system from adolescence to adulthood and the risk factors associated with the escalation of criminal justice involvement over time. We retrospectively linked offending records from 1994 to 2022 and mental health records from 2001 to 2022 for a cohort of 1556 adolescents identified through four health surveys in New South Wales, Australia. Transition probabilities were calculated using the Aalen-Johansen method, and the hazards of transition-specific covariates were estimated. The median age of adolescent entry was 15 years. The cohort was predominantly male (87.5%) and non-Indigenous (65.6%). Among incarcerated adolescents, 76.8% transitioned to adult incarceration. Transition probabilities were the highest among those aged 10–13 years. Among those with mental disorders, psychosis was associated with transitions to adolescent and adult incarceration. Other risk factors for future incarceration include being male, Indigenous, socio-economically disadvantaged, having a history of adolescent incarceration, and being diagnosed with substance use and behavioural disorders. Younger adolescents have higher transition probabilities to more intense criminal justice involvement. Legislative and policy reforms are needed to delay the onset of adolescent criminal justice involvement and ensure age-appropriate rehabilitative strategies to reduce recidivism. •Multi-state modelling can be used to assess criminal justice transitions from adolescence to adulthood.•Younger adolescents have higher probabilities of further incarceration after entry into the criminal justice system.•Adolescent incarceration is associated with adult incarceration and has a leveling effect regardless of age at entry.•Mental disorders increase the risk of incarceration during adolescence and adulthood.