The FBI collects these data through the Uniform Crime Reporting (UCR) Program.
These tables contain statistics for the entire United States. Because not all law enforcement agencies provide data for complete reporting periods, the FBI includes estimated crime numbers in these presentations. The FBI estimates data for three areas: Metropolitan Statistical Areas (MSAs), cities outside MSAs, and nonmetropolitan counties. The FBI computes estimates for participating agencies not providing 12 months of complete data. For agencies supplying 3 to 11 months of data, the national UCR Program estimates for the missing data by following a standard estimation procedure using the data provided by the agency. If an agency has supplied less than 3 months of data, the FBI computes estimates by using the known crime figures of similar areas within a state and assigning the same proportion of crime volumes to nonreporting agencies. The estimation process considers the following: population size covered by the agency; type of jurisdiction, e.g., police department versus sheriff’s office; and geographic location.
In response to various circumstances, the FBI has estimated offense totals for some states. For example, some state UCR Programs do not provide forcible rape figures in accordance with UCR guidelines. In addition, problems at the state level have, at times, resulted in no useable data. Also, efforts to convert to the National Incident-Based Reporting System (NIBRS) have contributed to the need for unique estimation procedures.
A summary of state-specific and offense-specific estimation procedures is available in the Estimation of state-level data section of the Methodology.
For the 2009 population estimates used in this table, the FBI computed individual rates of growth from one year to the next for every city/town and county using 2000 decennial population counts and 2001 through 2008 population estimates from the U.S. Census Bureau. Each agency’s rates of growth were averaged; that average was then applied and added to its 2008 Census population estimate to derive the agency’s 2009 population estimate.