This research utilised a range of deterministic and stochastic analyses to establish whether Queensland's juvenile justice system processes Aboriginal and non-Aboriginal young male offenders differently. The impetus for this research stemmed from the continued high rates of Aboriginal over-representation within Australia's criminal justice system, despite diversionary measures to reduce such over-representation, and a commitment by the Queensland Government to reduce by 50% the number of Aboriginal peoples in custody by the year 2011. There are two competing hypotheses concerning the cause of this over-representation, (i) external factors such as socioeconomic disadvantage, unemployment or substance abuse, or (ii) systemic disparity within the criminal justice system. For this research, disparity is defined as the unacceptable use of discrimination; discrimination can be appropriate if it is used to define or enhance a situation, such as discriminating between offenders who are recidivists and those who are first time offenders. The inappropriate use of discrimination occurs for example, when harsher sentences are issued to offenders based on non-legal factors such as race or gender. Systemic disparity is therefore used here to represent the inappropriate use of discrimination against an offender by the criminal justice system. The second hypothesis, one of systemic disparity, provided the framework for this research, which posed the following primary question: Is there quantifiable evidence to support the existence of disparity acting against young male Aboriginal offenders within Queensland's juvenile justice system? Two separate but complementary studies were designed to address this issue: the pathways study and the trajectory study. The pathways study utilised 20,648 finalised appearances for Aboriginal and non-Aboriginal young male offenders in Queensland's juvenile courts, during 1999 to 2003. Three custodial decision-making stages (police custody, remand, and sentencing) were examined and two questions initially posed: Does the custodial decision made at one stage of the juvenile justice system impact on a subsequent custodial decision-making stage? Does criminal history, Aboriginal status, offence type or an interaction of these factors significantly influence the probability of (i) detention in police custody (ii) court remand (iii) a custodial order at sentencing? It was recognised that other legally relevant factors such as family structure and stability, school attendance and community ties might also influence these custodial decisions; however, for the purposes of this research it was not possible to include these variables in the analyses. Controlling for criminal history, findings from logistic regression analyses indicated that being detained in police custody increased the odds of being remanded into custody, and being remanded into custody increased the odds of a custodial order. Whilst Aboriginal status was not a consistent factor at any of these three custodial stages, there was clear evidence of disparity acting against the young male Aboriginal offender, particularly early in their criminal career. To examine these disparities further, these three custodial stages were modeled as eight processing pathways: four of which resulted in a custodial order and four in a noncustodial order. Using this processing model, a third question was posed: Do young Aboriginal and non-Aboriginal male offenders have different custodial pathways? Findings indicated that Aboriginal and non-Aboriginal young male offenders were in general, processed along similar custodial pathways that did not include police custody, remand or a custodial order. However, young male Aboriginal offenders were less likely than equivalent non-Aboriginal offenders to have been processed along this pathway and more likely to be processed along the pathways that included remand. It was found that young offenders with a chronic criminal history were more likely to be processed along these remand pathways, and Aboriginal offenders were more likely to have a chronic criminal history than non-Aboriginal offenders; there was clear evidence of disparity at specific custodial stages of the system. In addition, as young male Aboriginal offenders progressed deeper into the system there was evidence of cumulative disparity, particularly along the remand pathways, meaning that the probability of being in custody increases as the offender progresses from one custodial stage to the next custodial stage. Given the existence of disparity, acting within the juvenile justice system and against the young male Aboriginal offender, it was important to formulate viable solutions to such disparity, particularly in light of the Queensland government's commitment to reduce Aboriginal offenders in custody by 50%. Deterministic analyses and computer simulations were used to test the viability of various reduction scenarios suggested by the data. Despite in some instances, different results from the deterministic analyses and the computer simulations, overall findings indicated that to reduce custodial disparity whether at the remand stage, the custodial order stage, or in custody overall (the summation of police custody, remand and custodial orders) that reducing remand, regardless of whether the young offender had been in police custody or not, was the best overall solution. The trajectory study built on the findings of the pathways study, which had identified criminal history as an important factor in the processing pathways of young male Aboriginal and non-Aboriginal offenders. Using the semi-parametric group based method, the criminal trajectories of Aboriginal and non-Aboriginal young male offenders in Queensland were modeled. These trajectories were based on the finalised appearances of two cohorts of young offenders aged 10 to 17 years of age: those born in 1983 and 1984 and who had turned 18 years of age in 2001 and 2002 respectively. All of these young male offenders had entered the adult system when they turned 17 years of age, and this data provided their complete juvenile history in Queensland. Prior analyses using this method had not considered Aboriginal status or race as a determining factor in these trajectory models, nor had these models been validated either internally or externally in published works. For this research, internal validity was considered as the correct classification of offenders into trajectory groups, and external validity as the ability to reproduce these results in a second or subsequent sample of juvenile offenders. Two questions were therefore posed in the trajectory study: Do young Aboriginal and non-Aboriginal male offenders have different criminal trajectories? Can the predicted model(s) be validated, both internally and externally? Initial findings indicated that the optimal trajectory models selected on prior knowledge and the Bayesian Information Criterion did not validate internally. This finding brought into question the trajectory results of other published works that had not internally validated their models. The models finally selected as optimal indicated that Aboriginal and non-Aboriginal young male offenders did not have a common criminal trajectory and could not be modeled as one population. Both Aboriginal and non-Aboriginal young offenders were modeled by a low-frequency group, a late-onset group, and a chronic trajectory group. However, the young male Aboriginal offender was more likely than the non-Aboriginal to have been in the chronic or the late onset group and less likely to have been in the lowfrequency group. External validation utilised an innovative but simple method that utilised all of the data in the modeling process along with a sample of this same data for validation purposes: 10% of the criminal profiles, which were characteristic of the trajectory groups, and a further 5% of randomly selected profiles were chosen for validation. All of the characteristic profiles, but only 50% of the randomly selected profiles were validated, and of the latter, the majority not validated was in the late-onset group. In total, 79.2% of the Aboriginal trajectories and 85.6% of the non-Aboriginal criminal trajectories were correctly externally validated. Overall, there are two important implications from this research for government. First, even though young male Aboriginal offenders are more likely to have a chronic criminal history than non-Aboriginal offenders, this factor does not account for all of the observed disparity acting against the young Aboriginal offender within Queensland's juvenile justice system: there is evidence of disparity within the system that is unaccounted for by either offence type or criminal history. Second, given this chronic criminal history, systemic solutions to systemic disparity whilst viable, will not ultimately resolve this problem: they are only short-term measures at the end of a very long justice system. Longer-term solutions are needed to address external factors such as socio-economic disadvantage, unemployment and substance abuse in Aboriginal communities, before these young people are exposed to the system. Continuing to concentrate on systemic solutions, to such an entrenched problem as Aboriginal overrepresentation and disparity, is a misdirection of system resources and is inconsistent with social justice.