Sources and methodology

Combined prison and local jail

Combined population of state prisons and local jails at year end 2019, including an adjustment to avoid double-counting people under state jurisdiction being held in local jails. Source: Bureau of Justice Statistics, Correctional Populations in the United States, 2019 Appendix Table 1 and Prisoners in 2019 Table 21 for territorial populations.

Youth

People younger than 21 detained or committed to juvenile residential placement facilities (not adult prisons or jails) because of justice system involvement as of October 24, 2018. The totals reported for states do not match the U.S. total due to rounding for anonymity. Source: Juvenile Residential Facility Census Databook: 2000-2018.

Indian Country jails

Average daily population of adults and youth held in jails in Indian country in June 2018. Nine facilities did not report data, so the totals reported for the states do not match the estimated U.S. total, which imputes data for the missing facilities. Source: Bureau of Justice Statistics, Jails in Indian Country, 2017-2018, Appendix Table 1.

Civil commitment

People convicted of sexual offenses who are detained or committed in “civil commitment centers” (typically prison-like facilities) under civil commitment laws after their sentences are complete. Source: An annual survey conducted by the Sex Offender Civil Commitment Programs Network, the results of which were shared with the Prison Policy Initiative.

Pre-trial evaluation

People involuntarily committed by the court to state psychiatric hospitals for evaluation of competency to stand trial. Survey data are only available for 37 states. Source: NRI report, Forensic Patients in State Psychiatric Hospitals, 1999-2016, pages 91-92. Arkansas count for pre-trial evaluation was corrected after consulting with an official in the state’s forensic psychiatry program to only include the 9 inpatient evaluations conducted in 2014.

Not guilty by reason of insanity

People involuntarily committed by the court to state psychiatric hospitals after being found Not Guilty by Reason of Insanity or Guilty but Mentally Ill. Survey data are only available for 37 states. Source: NRI report, Forensic Patients in State Psychiatric Hospitals, 1999-2016, pages 103-104.

Incompetent to stand trial

People involuntarily committed by the court to state psychiatric hospitals for evaluation or restoration services for incompetency to stand trial. Survey data are only available for 37 states. Source: NRI report, Forensic Patients in State Psychiatric Hospitals, 1999-2016, pages 98-99.

Federal

Population under authority of the Federal Bureau of Prisons (as of July 15, 2021) or U.S. Marshals Service (average daily population in fiscal year 2020). The combined population of 216,925 was reallocated to the states using a ratio of the state of legal residence for the BOP population as of 2019, based on the reuslts of FOIA request 2019-04597. Unlike other categories, this population is based on state of residence rather than jurisdictional authority. In addition, 9.07% of the people in Bureau of Prisons custody are identified as “foreign.” We did not reallocate this 9.07% of the custody population to the states, but we did include them in the U.S. total. Source: Federal Bureau of Prisons (BOP) Population Statistics and the U.S. Marshals Service 2021 Prisoner Operations Fact Sheet.

Immigration

The average daily population under the custody of Immigration and Customs Enforcement (ICE) in July 2021. We could not reallocate this population to states of residence as we did with other federal detainees, but included the population in the U.S. total incarceration rate. Source: Immigration and Customs Enforcement Detention Statistics.

Military

People under military correctional authority at yearend 2019. Source: Bureau of Justice Statistics, Prisoners in 2019 Table 19.

Total incarceration

The combined total of all confined populations reported in other columns.

Federal origin percentage

Percentage of people under federal Bureau of Prisons or U.S. Marshals Service authority reporting the given state as their state of legal residence, as of as of July 15, 2021. This was used to reallocate people listed under BOP and USMS jurisdiction back to the states. Source: FOIA request 2019-04597.

State population

Total resident population on April 1, 2020 from the Census Bureau 2020 Apportionment Data Table 2.

Incarceration rate

Number of people confined per 100,000 residents of each state (the national rate is based on the total number of U.S. residents).

Violent crime rate

Number of violent crimes per 100,000 residents of each state (the national rate is based on the total number of U.S. residents). Violent crime is defined as the cumulative rate of assault, robbery, sexual assault/rape, and homicide reported to law enforcement. Source: Federal Bureau of Investigation’s Crime in the United States, 2019 Table 5. For more information on how and why we measured “violent crime,” see the "Violent crime" analysis and methodology section of the report.