Interpreting demographics data
Each year through the Uniform Crime Report (UCR), the FBI collects voluntarily reported arrest data from the country’s 18,000+ police agencies. Included in this data series is information about the demographics of those arrested, including age, gender, race, and ethnicity. All demographic categories and permissible groups featured in this tool are defined by the UCR program. While the series is quite extensive, demographic information is not uniformly collected across all years (for example, ethnicity data have not been collected since 1991 and estimated data are slightly less recent than reported data), and the data can be sorted only by select demographic group combinations (for example, it is possible to study arrest trends among males aged 18-24, but not white females). On this page, users can learn more about which demographic groups are most affected by arrests by interacting with a series of visualizations that explore how demographic trends in arrests vary by offense type, time, and place.
More specifically, UCR datasets are broken down by the month in which an arrest occurred. As such, agencies can opt to report none (i.e., zero months), some (i.e., 1-11 months), or all (i.e., 12 months) of their data. Hover over the visuals below to see how many months of data were actually reported. 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. Additionally, when reporting arrest counts to the UCR program, agencies are required to specify arrestee ages and genders; however, reporting arrestee race and ethnicity is optional. As such, reported demographic trends may undercount arrest volumes, and/or not be representative of all policing practices. Hover over the visuals below to see the percentage of arrest records that feature corresponding race and ethnicity data. Alternatively, to avoid issues of undercounting, users can opt to view national-level FBI estimates. Based on UCR data availability, users can explore reported arrest demographics at the national, regional, state, county, and agency levels from 1980-2016. Users can also explore estimated arrest demographics at the national level from 1980-2014. 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. Lastly, rarely occurring errors present in UCR datasets (for example, an agency mistyping “1,000 arrests” in their UCR report when “100” actually occurred, or a true instance of missing data being misclassified as “0 arrests”) may also be present in this tool.