Exploring trajectories of offender harm: An alternative approach to understanding offending pathways over the life-course

Purpose: Contemporary life-course research predominantly classifies offenders according to patterns of offending volume over time, however it is not clear how useful these classifications are for identifying the most harmful offenders. The current study uses a novel methodology to explore trajectories of offending harm over the early life course, drawing on longitudinal offending data for an Australian birth cohort. Methods: Crime harm values from the modified Western Australian Crime Harm Index were applied to major offence types evident among offenders in the cohort (N = 27,079), from ages 10 to 30 years. Group-based trajectory modelling (GBTM) was applied to both to offences and harm values to determine discernible trajectories of offending and harm. Results: GBTM analyses indicated four distinct harm trajectories in the cohort: early adult peak high harm (1.6%); adult escalating harm (4.4%); declining moderate harm (5.9%); and low harm (88.2%). Low volume offenders comprised the largest number of offenders in the higher harm groups, while among chronic offender groups the profile of harm was very mixed. Conclusions: This study finds that the traditional offender classifications do not effectively identify high-harm offenders. Findings are discussed with respect to life-course conceptualisations of offender pathways and challenges in identifying high harm offenders.