Crime data and statistics

Uniform Crime Reporting Program Data [United States] (1960+)
Scope: Periodic nationwide assessments of reported crimes.  The UCR program was subsequently expanded to capture incident-level data with the implementation of the National Incident-Based Reporting System. The NIBRS data focus on various aspects of a crime incident. Gathering of hate crime data by the UCR program was began in 1990. Hate crimes are defined as crimes that manifest evidence of prejudice based on race, religion, sexual orientation, or ethnicity. In September 1994, disabilities, both physical and mental, were added to the list. Also see Missing Data in the Uniform Crime Reports, 1977-2000. Select data is also contained in Data-Planet Statistical Datasets.  Also available in an easy to use cumulative format. 1930-1959 are available as scans of the books.
Where is the documentation:  ICPSR site
Sample Size: Over 4,500 agencies reporting since 1998.
Unit of Analysis:

1. Agency-Level UCR Data

The agency-level data, where the unit of analysis is the police agency (or incident for Supplementary Homicide Reports and Hate Crime) and contain information on:

• Offenses known and clearances by arrest
• Property stolen and recovered.  Aggregated at the agency-level, report on the nature of the crime, the monetary value of the property stolen, and the type of property stolen.
• Supplementary Homicide Reports (SHR) provide incident-based information on criminal homicides. Contain information describing the victim(s) of the homicide, the offender(s), the relationship between victim and offender, the weapon used, and the circumstance of the incident.
• Police Employee (LEOKA) Data provide information about Law Enforcement Officers Killed or Assaulted in the line of duty. Provide in-depth information on the circumstances surrounding killings or assaults, including type of call answered, type of weapon used, and type of patrol the officers were on.
• Hate Crime Data includes number of victims and offenders involved in each hate crime incident, type of victims, bias motivation, offense type, and location type.
• Arrests by age, sex, and race
• Arson

2. Incident-Level UCR Data

Incident-level data are collected through the National Incident-Based Reporting System (NIBRS) component of the UCR. NIBRS collects data on each single incident and arrest within 24 offense categories made up of 52 specific crimes called Group A offenses. For each of the offenses coming to the attention of law enforcement, specified types of facts about each crime are collected. In addition to the Group A offenses, there are 10 Group B offense categories for which only arrest data are reported. More information about this study can be found in the NIBRS Resource Guide.  Note not all states participate in the program.

County-Level UCR Data

The county-level Uniform Crime Reporting files contain only arrests and crimes reported data and are distributed annually as 4 separate data files:

• Arrests, All Ages
• Arrests, Adults
• Arrests, Juveniles
• Crimes Reported

Beginning in 1993, an Allocated Statewide Data file is also distributed for each part above. The Statewide data files provide the amount of data from statewide agencies allocated to each county based on the county's share of the state population. These Statewide data files can also be used to "back out" the statewide counts if only the county total is desired.

Major Studies that have used this data :  ICPSR Related Publications Site.

State Participants in NIBRS: 2022, 2021, 2020, 2019, 2018, 2017, 2016, 2015, 2014, 2013, 2012 with history

Also see Jacob Kaplan's Concatenated Files: National Incident-Based Reporting System (NIBRS) Data, 1991-2022.

Also see Jacob Kaplan's Concatenated files on Uniform Crime Reporting