J. Lo1, J. Fleckman1, T. Shu1, K.P. Theall1, S. Taghavi1 1Tulane University School Of Medicine, New Orleans, LA, USA
Introduction: Mass incarceration imprisons over 1.2 million individuals across the U.S., notably disrupting family ties and community solidarity in affected neighborhoods. Previous studies have shown incarceration creates social disorder and instability in these neighborhoods leading to increased violence. With the rise in firearm homicide and suicide rates in recent years, there have been limited studies analyzing the effects of incarceration rates on firearm violence in communities. The present study aims to uncover a potential driver of firearm violence. We hypothesized that increasing incarceration rate is associated with increased firearm homicide and suicide rates in metropolitan U.S. cities.
Methods: In an ecological, longitudinal analysis of 51 U.S. metropolitan statistical areas (MSAs), we analyzed firearm data from 2017 to 2019 and incarceration rate data from 2016. Firearm homicide and suicide death rates per 100,000 were obtained from the CDC’s WONDER online database. Incarceration rates were obtained from the Vera Institute of Justice and Prison Policy Initiative. Primary outcome variables included firearm homicide and suicide rates for all ages and under 25 years of age. The association between incarceration rate and the change in firearm homicide and suicide rates between all years and by year was analyzed with linear regression models.
Results: The average homicide rate across MSAs was 8.20 per 100,000 (sd=6.18) in 2017, 7.74 per 100,000 (sd=6.13) in 2018, and 7.94 per 100,000 (6.19) in 2019. The average incarceration rate in 2016 was 468.39 per 100,000 (sd=220.63). MSA incarceration rate was associated with increased firearm homicide and firearm suicide rates, with a 10% increase in incarceration rate associated 0.04 increase in homicide rate (p=0.03) and a 0.03 increase in suicide rate (p=0.02) from 2017 to 2019. This varied when examining specific annual rates, with the strongest impact of incarceration rate on homicide rates seen in 2018 and 2019 and an impact in each year for suicide rates. When examining rates among those < 25 years of age, MSA incarceration rate was significantly associated with suicide rates, but not homicide rate.
Conclusion: Cities with higher rates of mass incarceration may also experience higher rates of firearm homicides and suicides. Implications of the study include advocating against policies centered on increasing prison sentencing to reduce gun violence in the United States. Additionally, the present study aims to provide evidence for incarceration rates as a possible driver of gun violence.