This is the first study to examine the circumstances and toxicology of violence-related deaths among justice-involved young people. In this large, whole-population cohort from Queensland, Australia, the proportion of deaths from violence (4%) was considerably lower than previous US studies (48-68%) [1, 2], but is comparable to a smaller Australian study that examined deaths after release from youth detention in Victoria (3%) [3]. From 2000 to 2016, the violence-related death rate among those aged 10-44 years (at the end of the study period the oldest person in the cohort was 42 years in age) in the general population in Australia was 1.5 per 100,000 population [21]. Although the proportion of deaths from violence in this cohort was comparatively small, the rate of violence-related death among justice-involved young people (6 deaths per 100,000 person-years) is substantially higher than the rate of death in the Australian general population.
There were clear sex differences in the circumstances of violence-related deaths. Among women, fatal violence was often prefaced by intimate partner violence or relationship breakdown. In comparison, among men, violence-related deaths commonly occurred after an altercation with a friend or acquaintance. Previous studies examining violence-related deaths in this population did not report on the person(s) who perpetrated the violence [1, 3, 4, 22]. Although, our finding is consistent with the gender differences in violence-related deaths in the general population both in Australia [23] and internationally [7]. While there are very few rigorously evaluated violence prevention interventions for young women involved in the youth justice system, a randomised controlled trial involving skill-building exercises and HIV prevention information was found to potentially reduce violence victimisation by helping adult women released from prison make healthier decisions about their relationships [24]. Additional evidence-based interventions that meet the needs of justice-involved young women and support them to stay safe from violence appear indicated and should be paired with universal policies that aim to foster healthy norms and attitudes towards women.
Most of the deaths from violence in the cohort involved the use of a weapon. The use of any weapon in a violent event is associated with an increase in severity of injuries [25]. Reducing the use of weapons may reduce the severity of injuries and risk of death sustained from violent events. Consistent with patterns of weapon use at the population level in Australia [26] and the United Kingdom (UK) [27], the most commonly reported weapon used in the cohort was a knife. There is limited evidence on effective interventions to reduce knife violence. A systematic review of knife crime among young people in the UK found that adverse childhood experiences, poor mental health, previous violence victimisation, having peers that carry knives, economic deprivation and unemployment were connected to young people carrying knives and perpetrating knife violence [28]. These factors are also common among young people who have contact with the youth justice system [29]. In our cohort, people who died from violence were commonly not employed, which is also a risk factor for violence victimisation in the general population, particularly for men [30].
Our finding is in contrast to previous US studies, which found that the vast majority of violence-related deaths among young people released from youth detention involved a firearm [1, 22]. This likely reflects the differences in firearm policies and availability between the US and Australia [31]. Limiting the availability and use of firearms through implementing restrictive firearm policies, such as in Australia [32], is associated with a decrease in violence-related deaths at the population level [32]. This difference in firearm policy may also be contributing to the greater number of violence-related deaths in the US cohorts compared to our study cohort.
Indigenous people were disproportionately impacted by violence-related death. This finding has parallels in the US context, where people who identified as Black or Hispanic were more likely to die from violence than other demographic groups [1, 22]. Indigenous people in Australia [33], and Black and Hispanic people in the US [34, 35], are overrepresented in the youth and adult criminal justice systems and in violence-related deaths at the population level. However, these groups are not homogenous, and each has different histories of racial oppression (e.g., colonisation, slavery). Diverting people away from the criminal justice system and redirecting funds towards community-based health and social services may be an opportunity for violence prevention. In Australia, community justice models that include justice-reinvestment programs may both reduce the overrepresentation of Indigenous people in the criminal justice system and reduce violence in Indigenous communities [36].
Although limited by the number of toxicology reports available, cannabis and alcohol were the most frequent substances detected in these violence-related deaths. Additionally, many of the contributing causes of death in this study were substance-related. Although previous studies on this population did not examine the toxicology of violence-related deaths [1, 3, 4, 22], alcohol use disorder during adolescence was identified as a risk factor for violence-related death [1]. Our findings are consistent with the association between alcohol and cannabis use and an increased risk of violence victimisation in the general population in Australia [12] and internationally [8]. Given the high prevalence of substance use disorders among justice-involved young people [10], the provision of targeted and age-appropriate therapeutic interventions to reduce harmful substance use – both in detention and in the community – may improve health and reduce violence victimisation in this population.
Strengths and limitations
This study used rigorous data linkage methods, a large whole-population cohort, and had an extended follow-up period (up to 23 years). Linking youth justice and coroner’s records improved our ascertainment of violence-related deaths among justice-involved young people, as many of the coroner’s reports did not explicitly mention the deceased’s involvement in the youth justice system [37]. Despite this, the study was limited by the small number of violence-related deaths in the cohort over the study period. While data from coroners’ investigations provided detailed information on violence-related deaths in the cohort, the information available differed between deaths, depending on a third party’s subjective assessment of its relevance, or lack thereof, to the death. Given the preventable nature of these deaths, there was a surprising lack of information reported for some variables (Table 2). Future studies may benefit from linking with police or court records to improve our understanding of the people who perpetrated the violence. Additionally, not all full-text reports were available for each death on the NCIS, which has been noted previously as a limitation of the NCIS [38]. While we linked to national death records, we examined youth justice contact in only one state in Australia (Queensland); it is unknown how representative these youth justice data are of other Australian states.