Gun Violence

Gun violence is a modern public health crisis in the US. We investigate how environments—on street fronts, neighborhoods, cities, states, and the nation—shape this national trauma.

Researchers have known for many decades that environmental conditions affect crime and violence within local areas. Our lab focuses on how environmental conditions in one place can contribute to gun violence in other places. We have found that counties have higher gun homicide rates if neighboring states have weaker gun laws; that gun shows cluster near the borders of states with stronger background check laws; and that guns flow from states with weak gun laws to states with strong gun laws. The implications are clear. Addressing gun violence requires prevention efforts that reach across borders.

  1. Reeping P, Rajan S, Morrison CN, Gobaud AN, Wiebe D, Branas CC. Gun-free zones and active shootings in the United States: A case-control study. The Lancet Regional Health – Americas, 2024;37:100837.

  2. Gobaud AN, Morrison CN, Branas CC, Jacoby SF, Kramer M, Adkins-Jackson PB. Measuring the effect of historical structural racism on community firearm violence in US cities. Social Science and Medicine, 2024;361:117355.

  3. Bushover B, Mehranbod CA, Roberts LE, Gobaud AN, Fish C, Eschliman E, Gao X, Zadey S, Morrison CN. Temperature and firearm violence in four US cities: Testing competing hypotheses. Injury Prevention, in press.

  4. Zadey S, Branas CC, Morrison CN. Gun violence: A global problem needing local solutions. The Lancet. 2024;403(10446):2783-2784.

  5. Roberts L, Hoofnagle MH, Bushover B, Gobaud AN, Mehranbod CA, Fish C, Morrison CN. Interstate Highway Connections and Traced Gun Transfers Between the 48 Contiguous United States. JAMA Network Open. 2024;7(4):e245662.

  6. Gobaud AN, Jacobowitz AL, Mehranbod CA, Sprague NL, Branas CC, Morrison CN. Place-based interventions and the epidemiology of violence prevention. Current Epidemiology Reports, 2022, 9:223-232.

  7. Gobaud AN, Mehranbod CA, Reeping PM, Bushover B, Morrison CN. Firearm assaults against US law enforcement officers in the line-of-duty: Associations with firearm ownership and state firearm laws. Preventive Medicine Reports, 2022, 30:102002.

  8. Gobaud AN, Morrison CN, Mehranbod CA, Hoofnagle MH. Gun shows and universal background check laws across state lines. Preventive Medicine, 2022: 107094.

  9. Mehranbod CA, Gobaud AN, Jacoby SF, Bushover B, Morrison CN. Historical redlining and the epidemiology of present-day firearm violence in the United States: A multi-city analysis. Preventive Medicine, 2022: 107207.

  10. Gobaud AN, Mehranbod CA, Dong B, Dodington J, Morrison CN. Absolute versus relative socioeconomic disadvantage and homicide: A spatial ecological case-control study of US ZIP codes. Injury Epidemiology, 2022, 9:7.

  11. Kaufman EJ, Wiebe DJ, Xiong A, Morrison CN, Seamon M, Delgado MK. Epidemiologic trends in fatal and nonfatal firearm injuries in the US, 2009-2017. JAMA Internal Medicine, 2021, 181(2):237-244.

  12. Reeping PM, Morrison CN, Rudolph KE, Goyal M, Branas CC. A comparison and analysis of seven gun law permissiveness scales. Injury Epidemiology, 2021, 8(1):2.

  13. Beard JH, Jacoby SF, Maher Z, Goldberg AJ, Kaufman EJ, Dong B, Morrison C. Changes in shooting incidence in Philadelphia between March and November 2020. JAMA – Journal of the American Medical Association, 2021, 325(13):1327-1328.

  14. Morrison CN, Kaufman EJ, Humphreys DK, Wiebe DJ. Firearm homicide incidence, within-state firearm laws, and interstate firearm laws in US counties. Epidemiology, 2021, 32(1):36-45.

  15. Kaufman EJ, Morrison CN, Branas CC. Reducing gun violence using alcohol-related convictions: “Never use alcohol, over-the-counter drugs or prescription drugs before or while shooting” [Commentary]. JAMA Internal Medicine. 2020; 180(1):43-44.

  16. Andrade EG, Hoofnagle MH, Kaufman EJ, Seamon MJ, Pah AR, Morrison CN. Firearm laws and illegal firearm flow between US States. Journal of Trauma and Acute Care Surgery, 2020, 88(6): 752-759.

  17. Dong B, Jacoby SF, Morrison CN, Wiebe DJ. Longitudinal heterogeneity in handgun carrying behavior among urban American youth: Intervention priorities at different life stages. Journal of Adolescent Health, 2019, 64(4): 502-508.

  18. Beard J, Resnick S, Maher Z, Seamon M, Morrison CN, Sims C, Smith R, Sjoholm LO, Goldberg A. Clustered arrivals of firearm injured patients in an urban trauma system: a silent epidemic. Journal of the American College of Surgeons, 2019, S1072-7515(19): 30254-30256.

  19. Kaufman EJ, Holena DN, Yang WP, Morrison CN, Jacoby SF, Seamon MJ, Sims CA, Wiebe DJ, Beard JH. Firearm assault in Philadelphia, 2005-2014: A comparison of police and trauma registry data. Trauma Surgery and Acute Care Open, 2019, 4: e000316.

  20. Beard JH, Jacoby SF, James R, Dong B, Maher Z, Goldberg A, Morrison CN. Examining mass shootings from a neighborhood perspective: An analysis of multiple-casualty events and media reporting in Philadelphia, United States, 2006-2015. Preventive Medicine, 2019, 129: 105856.

  21. Dong B, Branas CC, Richmond T, Morrison CN, Wiebe DJ. As violence unfolds: a space-time study of situational triggers of violent victimization among urban youth. Journal of Quantitative Criminology, 2020, 36(1): 119-152.

  22. Kaufman EJ, Morrison CN, Olson E, Humphreys D, Wiebe DJ, Martin N, Sims C, Hoofnagle MH, Schwab CW, Reilly PM, Seamon MJ. Universal background checks for handgun purchases can reduce homicide rates of African Americans. Journal of Trauma and Acute Care Surgery, 2020, 88(6): 825-831.

Study Publications