Youth violence is a significant public health problem.^1,2 Homicides are the third leading cause of death for U.S. youth (aged 14–24 years).³ Assault-related injuries are responsible for 600,000 emergency department (ED) visits among youth annually.³ In addition to negative health-related outcomes (e.g., substance use, post-traumatic stress disorder [PTSD], fatal injury),^4–6 youth violence has been associated with adverse social consequences, most notably criminal justice involvement.^7,8 Nearly 1.2 million youth were arrested in 2015, with 30% of arrests attributable to substance use, weapon, or violence-related offences.⁹ Disparities are significant, with homicide, violent injury, arrest, and incarceration rates persistently higher for black youth than similarly aged white youth.^1,3,10,11 Economic costs are also substantial, with interpersonal violence costs approaching $37 billion annually.¹²

The effects of an arrest and subsequent incarceration on healthy adolescent development are considerable. Such youth face loss of peer and parental social support, as well as elevated rates of school dropout, substance use, repeat arrest, and adult incarceration.¹³ Youth offenders have a 50% higher 5-year mortality than non-offenders, with rates increasing substantially as the extent of their involvement progresses from arrest to juvenile detention, incarceration, and transfer to adult court.14 Notably, even when such youth re-engage within their communities, they face low rates of employment, poor access to insurance/health care, family instability, and elevated rates of poverty.^11,15 These factors exacerbate the cycle of violence involvement, increasing the likelihood that they re-engage with violent behaviors that increase negative health and social outcomes.

Urban EDs that serve as the primary setting for treating assault-injured youth^1,16–18 have emerged as an important venue for violence prevention.^19–21 ED- and hospital-based violence prevention programs, recognizing the negative effect of criminal justice involvement on health outcomes, have begun to emphasize the reduction of arrest and incarceration as important outcome measures.^1,8,22–24 However, although prior longitudinal studies have characterized criminal justice outcomes among general youth populations,^25–27 none have examined the subpopulation of youth seeking assault-injury treatment. Prior ED/hospital-based studies of assault-injured youth have provided mixed results as to whether an assault injury is a marker for increased criminal justice involvement.^28,29 Such research has also been limited by non-comparable control groups,³⁰ convenience samples,³¹ and trauma registry²⁹ or self-report data.³² Further, among assault-injured youth seeking treatment, 55% report recent substance use.³³ Substance use is an important risk factor based on theories of problem behavior clustering,³⁴ the pharmacological effects of acute intoxication,³⁵ and the violent nature of the illicit drug trade.³⁶ Thus, an enhanced understanding of criminal justice outcomes among higher-risk drug-using youth following an assault injury is critical to implementing effective prevention strategies.

The primary study objective is to examine rates and characteristics of arrest among drug-using youth (i.e., ages 18–24 years) following ED treatment for assault as compared with a drug-using sample seeking care for other reasons. From prior work^5,6,37 and theory,³⁴ it is hypothesized that drug-using assault-injured youth will have higher arrest rates and that arrest risk will be associated with potentially modifiable risk factors, including higher severity substance use, mental health, and violence involvement. Results will aid the design of interventions focused on addressing multiple violence-related outcomes, including criminal justice involvement.

The Flint Youth Injury Study^5,6,33,38,39 is a 2-year longitudinal study characterizing substance use and violence outcomes among a consecutively obtained sample of assault-injured youth (original sample ages:14–24 years) with past 6-month drug use (AIG) and a comparison group (CG) of non-assaulted drug-using youth. This analysis focuses on arrests among the AIG and CG cohorts between ages 18 and 24 years. University of Michigan and Hurley Medical Center (HMC) IRBs approved study procedures; a NIH Certificate of Confidentiality was obtained.

Overall, 599 youth (AIG=349, CG=250) were enrolled in the longitudinal study. Baseline characteristics and the flowchart have been previously published.⁶ Of note, 75.6% of the CG patients were seeking care for a medical issue (e.g., abdominal pain), with the remainder seeking care for an unintentional injury (e.g., motor-vehicle crash). No differences were noted between the baseline cohorts with regards to age, sex, race, or SES. Follow-up rates were 85.5% at the 6-month, 83.8% at the 12-month, 84.3% at the 18-month, and 85.5% at the 24-month follow-up, with no differential follow-up.⁶ On average, 3.5% of follow-ups at each timepoint were conducted in prison/jail. Among the sample, 511 (AIG=299, CG=212) youth were aged ≥18 years at baseline and were included in this analysis. Among the analytic sample (n=511), 57.1% of youth were male, 58.3% identified as black, and 73.2% were on public assistance.

Risk of arrest in the 24 months following the ED visit was 47% higher in the AIG than the CG (38.1% vs 25.9%, RR=1.47, 95% CI=1.07, 2.02). Figure 1 depicts the Kaplan–Meier survival curve estimates for both the CG and AIG; from that it is apparent that the expected time until arrest is shorter for the AIG group. The AIG also had a higher average number of arrests per participant than the CG (2.00 vs 1.55, p<0.01) and a higher proportion of AIG youth had more than one arrest during the study (21.1% vs 9.0%, p<0.001). Table 1 presents descriptive data on the 313 arrests among 195 participants (with one or more arrests). Nearly 41% of arrests were for violent or weapon-related crimes. When compared with the CG, the AIG had a higher proportion of arrests for property crime. Among 313 arrests, 44.4% did not result in formal charges and for the 174 arrests where criminal charges were filed, 30.5% resulted in fines or monetary restitution, 23.6% involved jail/prison time, 17.2% involved probation, and 5.8% involved diversionary programs. No group differences for judicial disposition were identified.

Participants who were arrested were more likely than those not arrested to be male, have a baseline assault injury, binge drink, use marijuana, meet criteria for a drug use disorder, and report higher levels of community violence exposure (Table 2). No differences were noted for the other baseline characteristics or for other substance use and mental health variables.

Cox regression analysis demonstrating covariate effects on the hazard of arrest is shown in Table 3. The hazard of arrest was about 2.5 times larger among males. A diagnosis of assault injury and drug use disorder each corresponded to a 63% and 42% increased hazard, respectively. For each additional point on the community violence exposure scale, the hazard for arrest increased by ≅35%. Age, race/ethnicity, public assistance, and mental health diagnosis were not significantly related to the expected time until arrest. The proportional hazards assumption was tested by analyzing the Schoenfeld residuals and found to be tenable (x²=11.94, df=8, p=0.156).

This study identified that nearly 40% of high-risk youth seeking ED treatment for assault experience at least one arrest within the 24 months following their visit, a 47% higher risk than CG youth. Although comparisons are difficult as this is the first longitudinal study to examine arrests among a systematically sampled cohort of assault-injured drug-using ED youth, results are comparable or higher than case-control/retrospective studies.^8,22–24 Findings have implications for violence prevention. First, similar to research identifying that an assault injury increases the risk for violent injury recidivism,⁶ firearm violence,⁵ and substance use,³⁷ findings suggest that it is also a marker for identifying youth at elevated risk for negative criminal justice outcomes. Second, the finding that more than 20% of AIG participants experienced more than one arrest and that a quarter of the participants who were charged with a crime received jail/prison time (less than 6% were sent to a diversionary program) reinforces that once youth are engaged within the justice system, they have an elevated risk of recidivism and negative outcomes that perpetuate the cycle of violence. This is consistent with research demonstrating that criminal justice involvement disrupts the transitional milestones necessary for a healthy progression from adolescence to adulthood (e.g., education, employment, family formation)¹³ and with data indicating that youth who experience official court processing instead of diversionary programs had higher rates of subsequent violent and non-violent criminal activity and were more likely to have an adult criminal record.⁵⁶ This is particularly concerning in light of research showing that more severe criminal justice involvement (e.g., incarceration) is accompanied by higher mortality.¹⁴ Taken together, findings underscore the need for violence prevention initiatives that address risk for arrest and future incarceration as key outcome measures in parallel with violence.

Several hospital-based violence interventions focusing on intensive wrap-around services have demonstrated modest success reducing arrest and conviction rates for violent crimes during the post-injury period.^8,22,23 Although the optimal structure of such interventions continues to be a focus of research, study data may aid the identification of components critical to enhancing intervention efficacy. The finding that arrests were higher among those with an assault injury and that more than 40% of all arrests were related to violence- and weapon-related charges raises concern for retaliatory violence stemming from the ED visit. This is consistent with data demonstrating that the immediate post-injury period is a high-risk time for retaliatory violence^57,58 and that retaliation is a key motivation for youth violence, especially severe violence involving firearms.^58–60 In addition, almost half of assault-injured youth indicated that they did not believe the altercation leading to their ED visit was over, and a quarter indicated that they or their friends/family intended to seek retribution.³³ Thus, the need for violence initiatives to address retaliatory risk and include skills training on non-violent conflict resolution cannot be overstated.

Although all enrolled youth had drug use as a criterion of inclusion (96.8% reported marijuana use), those with a drug use disorder had a 42% higher risk of arrest. This, combined with the finding that a quarter of arrests were for drug- or alcohol-related offenses and that arrested youth had higher rates of binge drinking compared with those not arrested, emphasizes the need to address substance use and referral to treatment within violence prevention programs. Many hospital-based interventions, while showing promise, have not traditionally addressed substance use beyond referral to treatment.^{8,20,22,24,61–66} Yet, other researchers have demonstrated that single-session substance use^67–69 and combined multisession collaborative care interventions⁷⁰ addressing PTSD and associated comorbidities (e.g., substance use) are efficacious in reducing violence among lower at-risk youth. Thus, incorporating substance use treatment as a central component of interventions designed for higher-risk assault-injured youth may enhance efficacy, especially among youth in low-resource communities with limited access to treatment services.^71–73 Although mental health diagnoses were not predictive of arrest, it is notable that approximately 36% of youth met criteria for at least one diagnosis. This, combined with research establishing an association between PTSD and violence,^5,6 and studies demonstrating that providing ED youth with serious mental health disorders access to treatment reduces criminal justice involvement⁷⁴ emphasizes the need to incorporate access to mental health services within prevention programs.

Higher perceived community violence exposure was associated with an elevated risk of arrest, emphasizing the need for interventions crossing multiple socioecologic levels. Within a theoretic context, community-level interventions focused on increasing social capital and community engagement are thought to enhance overall community organization, leading to lower rates of problem behaviors (e.g., violence) and improving neighborhood safety.^75,76 Greening initiatives have demonstrated success with such an approach, decreasing rates of firearm violence, violent crime, and community stress, while improving perceptions of neighborhood safety.⁷⁷ Recent research has also demonstrated the strength of combining individual-level hospital interventions with broader community-wide interventions, such as mentoring programs, neighborhood greening, and community policing, finding that a comprehensive intervention package addressing multiple socioecologic levels can be successful decreasing violent crime and assault injuries.⁷⁶

Similar to prior research,^78,79 males had a greater risk of arrest. Despite this, females accounted for one quarter of those arrested and half of youth seeking assault treatment,³³ highlighting the need for interventions tailored for both sexes. Although SES was not associated with differential arrest risk, it is notable that more than 70% of youth reported receipt of public assistance, reflecting the high rates of poverty, unemployment and neighborhood disadvantage in this community. It is interesting to note, however, that AIG youth were noted to have higher rates of property-related crimes than the CG, highlighting monetary gain as a potential motivation for criminal activities. Future analyses should consider more sensitive SES measures as a means of exploring the role of poverty in criminal justice involvement. Interestingly, arrest rates did not differ by race/ethnicity, likely reflecting overall low variability between racial/ethnic categories in this sample.

Youth violence has been associated with multiple negative health and social outcomes, including criminal justice involvement. This study examines legal involvement of a cohort of assault-injured drug-using youth. The finding that rates of criminal arrest approach nearly 40% in the 24 months following the ED visit and that most relate to retaliatory violence, weapons, or substance use suggests that prevention efforts focused on reducing violence and substance use may have the potential to reduce criminal justice involvement and negative health-related outcomes.