Enhancing Gun Violence Surveillance with Endemic-Epidemic Modeling: A Case Study in Washington, D.C.

Gun violence is a persistent public health concern in the United States, particularly in disadvantaged neighborhoods facing social and economic hardships. Washington, D.C., ranks among cities with the highest gun violence rates, incurring an estimated annual economic burden of over $2 billion. This issue is shaped not only by place-based factors but also by dynamic processes, such as local recurrence and spillover from nearby events that elevate short-term risk. This study utilized an endemic-epidemic model to disentangle contributions to background risk versus dynamic processes, analyzing approximately 24,000 firearm-related incidents in D.C. census tracts over 596 weeks from January 2014 to July 2025. Time-varying structural factors, including social vulnerability metrics and alcohol outlet access, were considered. Key findings revealed that ~ 79% of gun violence incidents were driven by endemic factors linked to long-term structural vulnerabilities, notably high alcohol outlet density and low access to essential resources. Conversely, short-term spikes in violence were influenced significantly by recent incidents within a tract, with minimal spillover effects from neighboring areas. We also mapped tracts and weeks that exceeded baseline predictions to highlight areas experiencing sustained surges in gun violence, providing valuable insights for future community alerts. These findings underscore the need to address localized issues and persistent long-term risk factors. Effective solutions must prioritize enhancing neighborhood conditions and community resources. Addressing these upstream or "root cause" factors is crucial in a public health approach to gun violence, emphasizing the importance of considering structural and social determinants, and dynamic processes influencing spikes in violence.