8.67% of police agencies in
Interpreting data reported
Each year through its Uniform Crime Report (UCR) program, the FBI collects and publicly disseminates voluntarily reported arrest and clearance rate data from the country’s 18,000+ police agencies. However, for a variety of reasons—including lack of technology or resources, unique approaches to publicly distributing data, incompatible offense definitions, and/or fundamental issues with open policing data—not all police agencies report their data to the UCR program. Further, some agencies report only partial data by submitting arrest counts and clearance rates for one to 11 months in a given year, rather than the full 12 months. Underreporting has severe consequences for the accuracy and availability of policing data across the country, sometimes making the complete picture of arrest trends difficult. On this page, users can learn more about the gaps in available policing data by interacting with a series of visualizations that explore reported data trends across time and place.
More specifically, users should note that months reported was calculated and validated using publicly available data, which may not reliably a) indicate when multiple agencies report their data together, or b) specify months in accordance with UCR reporting instructions. Lastly, data are labeled as “not applicable” when relevant information was not collected in a given year, and “missing” when relevant information was collected but a location did not report it.