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Survey Methodologies

NIBRS Estimation Project

Beginning with the 2021 data year, estimates of crime known to law enforcement will be based solely on data provided to the FBI's National Incident-Based Reporting System, or NIBRS. In 2021, 67.9% of all crime-reporting law enforcement agencies were reporting to NIBRS, covering 65.7% of the U.S. population.

NIBRS Coverage, 2017 to 2021

To calculate a national crime rate based on NIBRS data, BJS, in partnership with the FBI and...

Survey of Prison Inmates (SPI)

The Survey of Prison Inmates (SPI) is a periodic, cross-sectional survey of the state and sentenced federal prison populations. Its primary objective is to produce national estimates for the state and sentenced federal prison populations across a variety of domains, including but not limited to demographic characteristics, current offense and sentence, incident characteristics, firearm possession and sources, criminal history, socioeconomic characteristics, family background, drug and...