The authors used publicly available data from local governments and police agencies to examine crime by category from January 1, 2023, to June 30, 2024. The initial list of cities was created using the most recent year of U.S. census data available. After compiling a list of cities with publicly available crime data in each of the eight categories described above, the cities were categorized by how frequently their data were updated, the type of data reported (i.e., raw incident data, aggregated monthly counts, or quarterly reports), and how and which crimes were reported (NIBRS offense codes or other categories). Project criteria required that cities report incident-level data and update the data frequently, with no regular severe lags. 

The data are reported here in a minimally adjusted format. All data from the 49 U.S. cities available were normalized such that the eight crime categories included the same data across all cities. Data from Honolulu, Hawaii, was missing for much of 2023, so Honolulu was excluded from the study. Data from Hartford, Connecticut; Charleston, South Carolina; Burlington, Vermont; and Atlanta, Georgia, were missing for more than half of the first six months of 2024 and were excluded. Within the 49 cities included in the analysis, missing data for short periods was imputed in two ways. For gaps of less than five days or less than 15 percent of one-month, missing data were assumed to be missing completely at random and imputed as the value of the previous valid day. For gaps at the end of the data series, missing data were imputed as the average of all prior valid reported days in 2024. There were 231,000 valid observations (equivalent to one day of reported data per city). Three observations showed extreme values in aggravated assault (more than ten times the magnitude greater than any prior reported day), and these values were winsorized at 10. 

We found substantial variation across the cities in the panel. This suggests that two causal mechanisms are affecting national crime statistics. First, national crime statistics consistently show that violence peaked in 2021-2022 and has declined from that peak. This also indicates that macro forces are affecting crime and violence across the United States. These macro factors likely include a “return to business as usual” after the COVID-19 pandemic disruptions for local governments, which include police, courts, and schools. Other widely hypothesized macro factors include substantial federal government investments in general support for local governments and specific support for crime prevention and intervention measures, including unprecedented investments in community violence interventions.  

Second, the results show substantial variation at the city level, suggesting the micro forces specific to those cities are either enhancing macro trends or suppressing those factors. These micro forces likely fall into two categories. First, the macro forces described above have been unevenly implemented in cities. Second, crime and violence are hyper-local phenomena, and the momentum of prior pandemic-related violence may exceed the effect of more recent prevention and intervention policies and practices. 

Overall, the decline in several major categories of crime observed in the first half of 2024 is unprecedented in national crime statistics. It is imperative that we make efforts now to understand the why and how of this change. With that understanding, our cities, states, and policies will be best prepared for today and the future.