Article  |  Law enforcement

About Uniform Crime Reporting Program data

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The FBI’s Uniform Crime Reporting (UCR) Program is the official source of nationwide crime data and can be used to examine current patterns and trends over time. The Illinois UCR Program provides state-specific data. Those who use the programs to study crime trends should become familiar with the data source, its method of collection, and caveats needed to ensure proper data context.

Uniform Crime Reporting Program

The Uniform Crime Reporting Program is a voluntary, nationwide law enforcement data collection program maintained by the FBI since 1930. UCR Program goals include generating data that can inform law enforcement policy and planning and offering information about crime to entities, including, but not limited to, government agencies, researchers, the media, and the public. Statistical crime data from more than 18,000 law enforcement agencies—including state, county, tribal, and local police departments, as well as railroads, forest preserves, universities and colleges, park districts, and hospitals that employ sworn police officers—are submitted to the FBI.1

The FBI collects criminal offense and arrest data through the UCR program from law enforcement agencies in 50 states as well as the District of Columbia and three American territories—American Samoa, Guam, and Puerto Rico. In Illinois, the Illinois State Police (ISP) is responsible for submitting data gathered from Illinois law enforcement agencies to the FBI.

The FBI collects data on eight offenses for the UCR Program which are often referred to as Part 1 offenses or Index crimes—violent and property offenses that occur with regular frequency and are likely to come to the attention of police. These offenses are categorized into two types:

  1. Violent index offenses, including murder/non-negligent manslaughter, rape, robbery, and aggravated assault.
  2. Property index offenses, including burglary, theft, motor vehicle theft, and arson.

In addition to submitting data on Part 1 offenses, some law enforcement agencies across the country provide data on Part 2 offenses, which are less serious and encompass all other offenses.3 Data on Part 2 offenses are not collected by the Illinois State Police and therefore not submitted to the FBI.4

Data collection changes

The following changes have been made since the inception of the UCR program:

  • Two offenses were added:
    • Hate crime offenses in 1990.
    • Human trafficking-related offenses—coerced commercial sex acts and involuntary servitude—in 2013.5
  • The definition of rape was changed in 2013:
    • The term “forcible” was removed.
    • Male victims were added.
    • Other forms of sexual penetration were added.6


Once compiled from state-level submissions, the FBI publishes UCR data in Crime in the U.S., an annual report that summarizes the findings and arranges the data in tables. Criminal justice policy makers, criminal justice practitioners, and the public rely on the information contained in Crime in the U.S. to broaden their comprehension of national crime trends.7

At the same time, states publish their own annual UCR crime reports to disseminate information on state crime trends. ISP publishes Illinois UCR data in its annual report, Crime in Illinois, which includes data from reporting law enforcement agencies in each county. Illinois county-level UCR data are also available on the Authority website dating back to 1982.

Data reporting methods

The FBI’s UCR program uses four data collection subprograms to gather data and generate annual reports: the Law Enforcement Officers Killed and Assaulted (LEOKA) Program; the Hate Crime Statistics Program; the National Incident Based Reporting System (NIBRS), and the Summary Reporting System (SRS).8

The FBI uses LEOKA to collect and publish data through an annual report called Law Enforcement Officers Killed and Assaulted, which has been published since 1982. The Hate Crime Statistics Program is used to collect data on offenses motivated by a bias against someone’s race or ethnicity, religion, sexual orientation, or disability. Data collected are summarized and published in an annual report.

The FBI’s UCR program relies on both NIBRS and SRS to collect arrest and offense data from law enforcement agencies. NIBRS is an incident-based reporting system that allows agencies to collect detailed data on crime, including victim and offender demographics and incident information, for all reported offenses. SRS, on the other hand, allows law enforcement agencies to tally the number of occurrences of Part 1 offenses as well as the number of arrests for Part 1 and Part 2 offenses, on a monthly basis to produce aggregate totals for each offense category. These aggregate counts are submitted to the FBI for inclusion in the annual Crime in the U.S. report.

In total, 34 states are NIBRS compliant, 16 of which are fully compliant (all agencies in the state report via NIBRS), while the remaining 18 states submit both SRS and NIBRS data to the UCR program for inclusion in the annual Crime in the U.S. report.9

In most cases, Illinois law enforcement agencies use SRS to report to ISP and ISP uses SRS to report to the FBI. However, the FBI prefers that agencies report their data via NIBRS as it provides the most detailed information. The FBI has mandated that all states use NIBRS by 2021. Thus, Illinois will likely shift from SRS to NIBRS sometime in the next few years.10


While the UCR Program is considered to be a reliable and comprehensive source of information, it has its limitations. First, users should be aware that only certain serious violent and property crimes are collected, chosen for their regular occurrence and their likelihood of being reported to the police.

Second, crime often goes unreported to police. Available data may misrepresent actual crime rates.

Third, agencies use the “hierarchy rule,” which stipulates that only the most serious offense committed during a criminal incident must be reported. While offenders may commit and be charged with multiple law violations within an incident, only the most serious violation is reported to the UCR Program.

Fourth, lack of reporting or irregular reporting by states can limit the accuracy of UCR data, while technological problems, data system changes, and staff turnover may prevent agencies from reporting accurately or at all.11

These factors may indicate an undercount of UCR data when compared to actual occurrences of crime.

In addition, certain subprograms—such as the SRS—do not allow data on individual incidents, age, race, or gender to be submitted; data compiled by states that use the SRS exclusively, including Illinois, are incomplete.12

Due to these limitations, crime trends suggested by UCR data may not be representative of the entire population or reflect the true occurrence of crime.13

Illinois UCR Program

In 1969, a state law was passed requiring ISP to collect Part 1 Index offense data from all Illinois law enforcement agencies on a monthly basis14 [20 ILCS 2630/8].15

Data collection changes

In the past two decades, ISP has expanded the range of data compiled in I-UCR:

  • In 1994, ISP began requiring that law enforcement agencies report drug arrest data to I-UCR.16
  • In 1996, ISP began collecting data on domestic offenses, attacks against school personnel, and hate crimes, which was mandated by state statute [50 ILCS 709/5]. Additionally, ISP began the voluntary collection of data on crimes against children; however, reporting on crimes against children ended in 2013 to lessen the burden on agencies.17
  • In 2014, ISP added two human trafficking crime categories to the UCR Program: coerced commercial sex acts and involuntary servitude.18
  • In 2014, ISP adopted the FBI’s UCR Program expanded definition of rape and changed the name of that offense category from the previous terminology of criminal sexual assault.19
  • In 2014, ISP added a new school incidents supplemental report that expanded reporting of offenses against school personnel to include incidents of intimidation, drug use, and firearm incidents in schools.20
  • In 2016, ISP re-instituted Supplemental Homicide Reporting, pursuant to a new state law [50 ILCS 709/5],21 to collect detailed victim, offender, and incident information on each reported homicide.
  • In 2016, ISP began mandating law enforcement agencies to report incidents of death occurring during the course of an arrest, pursuant to a new state law [50 ILCS 709/5].22
  • In 2017, ISP will begin collecting officer-related non-fatal shooting incidents, pursuant to a new state law [50 ILCS 709/5].23

Reporting developments

Some Illinois law enforcement agencies were unable to make the necessary definition and hierarchical changes to their reporting systems in 2015, and as a result, fewer agencies reported data to ISP.24 In addition, data submitted by agencies that do not follow federal definitions and guidelines are excluded from Crime in Illinois.25

Between 2005 and 2015, the number of reporting agencies dropped 34 percent, from 1,119 to 741, due to a number of law enforcement agencies closing, merging with one another, or being unable to comply with reporting requirement (Figure 1).26

Three-quarters of all the Illinois agencies submitted data in 2015, accounting for 98 percent of the state population.27 Most agencies that did not report data were based in less populated jurisdictions and the decrease in number of reporting agencies had a minimal impact on the reliability and generalization of the data.

Summary and implications for policy and practice

Crime in Illinois is considered Illinois’ official source of crime statistics and provides the most comprehensive data available. While limitations to I-UCR data exist in terms of scope, the data are, for the most part, correctly reported and most of the Illinois population is represented.28

Accurate and reliable I-UCR data reporting by all local law enforcement agencies in Illinois allows policymakers and practitioners to identify and address crime trends across the state. Agencies that properly report data enjoy the added advantage of federal Edward Byrne Memorial Justice Assistance Grant Program funding eligibility.

Two practical changes would strengthen the I-UCR Program. First, the FBI provides guidelines to law enforcement agencies on proper data collection.29 ISP should resume offering training to law enforcement agencies on UCR guidelines as funding allows. This will be of particular importance in light of the newly instituted reporting mandates.30 Second, beginning in 2021, UCR data will be accepted only through NIBRS; 31 action toward statewide NIBRS implementation should be undertaken by local law enforcement agencies.

Once reporting is conducted through NIBRS, criminal justice policy makers, practitioners, researchers, and the public will have access to detailed information that will allow them to more closely examine trends and issues emerging in the criminal justice system.

  1. Federal Bureau of Investigation. (2014). Crime in the United States 2014: about the uniform crime reporting program. Retrieved from
  2. Federal Bureau of Investigation. (2014). Crime in the United States 2011: Offense definitions. Retrieved from
  3. T. Hickman, personal communication, October 15, 2015.
  4. Federal Bureau of Investigation. (2014). Crime in the United States 2014: about the uniform crime reporting program. Retrieved from
  5. Federal Bureau of Investigation. (2013). Uniform crime reports, rape addendum. Retrieved from
  6. Federal Bureau of Investigation. (2014). Crime in the United States 2014: about the uniform crime reporting program. Retrieved from
  7. Federal Bureau of Investigation. (2014). About the UCR program. Retrieved from
  8. D. Fouch, personnel communication, September 12, 2016.; Note: Compliance means that state NIBRS record management systems are compatible with the FBI specifications for reporting. Compliant states include Arizona, Arkansas, Colorado, Connecticut, Delaware, Kansas, Kentucky, Idaho, Iowa, Louisiana, Main, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, New Hampshire, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia. Washington, West Virginia, and Wisconsin.
  9. T. Hickman, personal communication, October 15, 2015.
  10. Federal Bureau of Investigation. (2016). A Word about UCR data. Retrieved from
  11. Federal Bureau of Investigation. (2014). FBI national incident based reporting system, the basics. Retrieved from
  12. Maltz, M. D. (1999). Bridging gaps in police crime data. Washington, DC: U.S. Department of Justice, Office of Justice Programs, Bureau of Justice Statistics.
  13. T. Hickman, personal communication, October 15, 2015.
  14. Illinois State Police. (2015). Crime in Illinois. Retrieved from
  15. T. Hickman, personal communication, October 15, 2015.
  16. T. Hickman, personal communication, October 15, 2015.
  17. Illinois State Police. (2015). Crime in Illinois. Retrieved from
  18. Illinois State Police. (2015). Crime in Illinois. Retrieved from
  19. Illinois State Police. (2015). Crime in Illinois, school incidents. Retrieved from
  20. Illinois State Police (2016). New 2016 reporting elements. Retrieved from
  21. Illinois State Police (2016). New 2016 reporting elements. Retrieved from
  22. Illinois State Police (2016). New 2016 reporting elements. Retrieved from
  23. Illinois State Police. (2015). Crime in Illinois. Retrieved from
  24. Illinois State Police. (2015). Crime in Illinois. Retrieved from
  25. T. Hickman, personal communication, October 14, 2015.)
  26. Illinois State Police. (2015). Crime in Illinois. Retrieved from
  27. T. Hickman, personal communication, October 15, 2015.
  28. Federal Bureau of Investigation. (2014). A word about UCR data. Retrieved from
  29. T. Hickman, personal communication, October 14, 2015.
  30. T. Hickman, personal communication, October 14, 2015.

Erica Hughes

Erica Hughes was an Authority research analyst. She received a Bachelor of Science in Human Resources and Family Studies at the University of Illinois Champaign-Urbana and a Master of Arts in Criminal Justice at University of Illinois Chicago. Her areas of interest include juvenile justice, victims, victim services, and college campus crime. Ms. Hughes was with the Authority since 1998.