DOI: 10.3886/icpsr38690
title: Uniform Crime Reporting Program Data: National Incident-Based Reporting System, [United States], 2021
title: Archival Version

description: The National Incident-Based Reporting System (NIBRS) is a
part of the Uniform Crime Reporting Program (UCR), administered by the
Federal Bureau of Investigation (FBI). In the late 1970s, the law
enforcement community called for a thorough evaluative study of the
UCR with the objective of recommending an expanded and enhanced UCR
program to meet law enforcement needs into the 21st century. The FBI
fully concurred with the need for an updated program to meet
contemporary needs and provided its support, formulating a
comprehensive redesign effort. Following a multiyear study, a
"Blueprint for the Future of the Uniform Crime Reporting Program" was
developed. Using the "Blueprint," and in consultation with local and
state law enforcement executives, the FBI formulated new guidelines
for the Uniform Crime Reports. The National Incident-Based Reporting
System (NIBRS) was implemented to meet these guidelines. 
NIBRS data as formatted by the FBI are stored in a single file. These data are organized by various segment levels (record types). There are six main segment levels: administrative, offense, property, victim, offender, and arrestee. Each segment level has a different length and layout. There are other segment levels which occur with less frequency than the six main levels. Significant computing resources are necessary to work with the data in its single-file format. In addition, the user must be sophisticated in working with data in complex file types. While it is convenient to think of NIBRS as a hierarchical file, its structure is more similar to a relational database in that there are key variables that link the different segment levels together.
NIBRS data
are archived at ICPSR as 11 separate data files per year, which may be
merged by using linkage variables. Prior to 2013 the data were archived and distributed as 13 separate data files, including three separate batch header record files. Starting with the 2013 data, the FBI combined the three batch header files into one file. Consequently, ICPSR instituted new file numbering for the data. NIBRS data focus on a variety of
aspects of a crime incident. Part 2 (formerly Part 4), Administrative Segment, offers
data on the incident itself (date and time). Each crime incident is
delineated by one administrative segment record. Also provided are
Part 3 (formerly Part 5), Offense Segment (offense type, location, weapon use, and bias
motivation), Part 4 (formerly Part 6), Property Segment (type of property loss, property
description, property value, drug type and quantity), Part 5 (formerly Part 7), Victim
Segment (age, sex, race, ethnicity, and injuries), Part 6 (formerly Part 8), Offender
Segment (age, sex, and race), and Part 7 (formerly Part 9), Arrestee Segment (arrest
date, age, sex, race, and weapon use). The Batch Header Segment (Part 1, formerly Parts
1-3) separates and identifies individual police agencies by
Originating Agency Identifier (ORI). Batch Header information, which
is contained on three records for each ORI, includes agency name,
geographic location, and population of the area. Part 8 (formerly Part 10), Group B
Arrest Report Segment, includes arrestee data for Group B crimes.
Window Segments files (Parts 9-11, formerly Parts 11-13) pertain to incidents for which the
complete Group A Incident Report was not submitted to the FBI. In
general, a Window Segment record will be generated if the incident
occurred prior to January 1 of the previous year or if the incident
occurred prior to when the agency started NIBRS reporting. As with the
UCR, participation in NIBRS is voluntary on the part of law
enforcement agencies. The data are not a representative sample of
crime in the United States.
Recognizing many differences in computing resources and that many users will be interested in only one or two segment levels, ICPSR has decided to make the data available as multiple files. Each NIBRS segment level in the FBI's single-file format has been made into a separate rectangular ASCII data file. Linkage (key) variables are used to perform analyses that involve two or more segment levels.
If the user is interested in variables contained in one segment level, then the data are easy to work with since each segment level file is simply a rectangular ASCII data file. Setup files are available to read each segment level. Also, with only one segment level, the issue of unit of analysis is greatly simplified.
However, if the user is interested in variables that are contained on two or more segment levels, then it is necessary to merge files, decide on the unit of analysis, and decide on the number of records per level to read. These are decisions that are necessary regardless of whether the data are stored in one large file or in separate files. Examples of working with two or more segment levels are included on the National Archive of Criminal Justice Data (NACJD) Website.
Consider an analysis involving variables from the victim (04) and offender (05) segment levels. Three units of analysis are available: the victim, the offender, and the incident itself. In addition, there may be up to 999 victim records per incident and up to 99 offender records per incident. The vast majority of incidents have only one or two victims and offenders. If the user does not limit the number of records read per incident, the analysis file will contain mostly missing data and will be excessively large. In fact, the analysis file could end up being much larger than all the segment levels combined. So in this case the user must determine both the unit of analysis and the number of records per segment level to be read, and then merge the victim and offender files accordingly.
description: Uniform Crime Reporting (UCR) is a city, county, state, and Federal law enforcement program. This Program provides a nationwide view of crime based on the submission of crime information by law enforcement agencies throughout the country. The crime data are submitted either through a state UCR Program or directly to the national UCR Program, which is administered by the FBI. For over half a century, the data have been used in law enforcement administration, operation, and management, as well as to indicate the levels and nature of crime in the United States.
In the 1920s, the International Association of Chiefs of Police (IACP) envisioned the need for statistics on crime in our Nation. The Committee on Uniform Crime Records of the IACP developed this national data collection effort in 1930 and continues to work with the FBI in its efforts with UCR today. During that same year, the IACP was instrumental in gaining congressional approval, which authorized the FBI to serve as the national clearinghouse for statistical information on crime. The National Sheriffs' Association, in June 1966, established a Committee on Uniform Crime Reporting to work with the FBI and to encourage sheriffs throughout the country to participate fully in the Program.
Throughout its first 60 years of operation, the UCR Program remained virtually unchanged in terms of the data collected and disseminated. As time progressed, a broad utility evolved for UCR data, and law enforcement expanded its capabilities to supply crime information. In the late 1970s, the law enforcement community called for a thorough evaluative study of UCR with the objective of recommending an expanded and enhanced UCR Program to meet law enforcement needs into the 21st century.
The FBI fully concurred with the need for an updated Program to meet contemporary needs and provided its support, formulating a comprehensive redesign effort. Following a multi year study, a "Blueprint for the Future of the Uniform Crime Reporting Program" was developed. Using the "Blueprint" and in consultation with local and state law enforcement executives, new guidelines for Uniform Crime Reports were formulated. The National Incident-Based Reporting System (NIBRS) is being implemented to meet these guidelines.
NIBRS will offer law enforcement and the academic community more comprehensive data than ever before available for management, training, planning, research, etc. The implementation of NIBRS will be at a pace commensurate with the resources, abilities, and limitations of the contributing law enforcement agencies. Since Uniform Crime Reporting, in particular NIBRS, is voluntary the pace of NIBRS implementation will be affected by the willingness of law enforcement agencies to participate.
description: The National Incident Based Reporting System (NIBRS) is an incident-based reporting system for crimes known to the police. For each crime incident coming to the attention of law enforcement, a variety of data are collected about the incident. These data include the nature and types of specific offenses in the incident, characteristics of the victim(s) and offender(s), types and value of property stolen and recovered, and characteristics of persons arrested in connection with a crime incident.
The data for the NIBRS are submitted voluntarily by city, county, and state law enforcement agencies. Some agencies receive forms directly from the FBI and return them directly to the FBI. Many others receive forms from state collecting programs and return these forms to those programs. The state programs, in turn, forward the reports to the FBI. Reports are sent out and collected on a monthly basis.
Once received, the FBI checks the agencies' reports for completeness and arithmetical accuracy. If an unusual fluctuation is detected in an agency's crime count, the FBI compares those counts with counts from previous reports or compares the frequencies to those of agencies similar to the agency in question. When necessary, law enforcement agencies are contacted to correct or explain the figures.
description: Incident Reports
<strong>Group A Offenses</strong>
Each Group A Incident Report can contain up to six distinct records, each of which is referred to as a segment. Most segments can occur multiple times for a given crime incident. An incident report may consist of many possible combinations of circumstances ranging from a simple one administrative, offense, victim, and offender situation, to a complex set of multiple offenses, property losses, victims, offenders, and arrestees. In addition, each of the victims may not be involved in each of the offenses. In other words, one, some, or all of the victims may be connected to each applicable offense.
<strong>Group B Offenses</strong>
There are 10 Group B offense categories. Only arrestee data are reported for Group B Crimes.
<strong>Window Segment Levels</strong>
Window Segment Levels
Window Segments reflect data in which the complete Group A Incident Report was not submitted to the FBI; rather, only a portion of the incident was submitted. A Window Segment record will be generated if the incident occurred prior to January 1 of the previous year or the incident occurred prior to when the agency began submitting NIBRS data to the FBI. Window Segments reflect data in which the complete Group A Incident Report was not submitted to the FBI; rather, only a portion of the incident was submitted. A Window Segment record will be generated if the incident occurred prior to January 1 of the previous year or the incident occurred prior to when the agency began submitting NIBRS data to the FBI.
Segments
<strong>Administrative Segment</strong>
Administrative Segment (Level 01) - The administrative segment of the Group A Incident Report allows the national UCR Program to uniquely identify each criminal incident reported under NIBRS, along with common characteristics of all offenses within each incident, e.g., the date and hour the incident occurred. Each crime incident has one administrative segment record. Thus, the number of crime incidents included in NIBRS data is generally equal to the number of administrative records.
<strong>Offense Segment</strong>
Offense Segment (Level 02) - All offenses associated with a crime incident, up to ten, are listed on separate records. In NIBRS, all Group A offenses occurring in an incident are to be reported. Care must be taken to identify all such offenses involved in an incident. For example, a rape case might also involve the crimes of motor vehicle theft and kidnapping, and they should all be reported. Care must also be taken to ensure that each offense which is reported is a separate, distinct crime, rather than just a part of another offense. For example, every robbery includes some type of assault; because the assault is an element which makes up the crime of robbery, only the robbery should be reported. If during a robbery, however, the victim is forced to engage in sexual relations, both robbery and forcible rape should be reported, as forced sexual intercourse is not an element of robbery. Burglary is another example in that it almost always includes a larceny offense. Because burglary is defined in terms of theft, only the burglary is to be reported. Information on at least one offense must be included in each Group A Incident Report.
Example 1: If an incident involved robbery and rape, two sets of offense data should be reported - one with the UCR offense code for robbery (120) and the other for forcible rape (11A).
Example 2: Even if two females were raped in Example 1 only one set of offense data should be reported with the offense code 11A. The two rape victims would be recorded in the victim data portion of the report. That is, an offense of forcible rape occurred, and there were two victims.
<strong>Property Segment</strong>
Property Segment (Level 03) - Property data are collected to describe the type, value, and (for drugs and narcotics seized in drug cases) quantity of property involved in the incident. Each property segment record contains information on a combination of TYPE OF PROPERTY LOSS - PROPERTY DESCRIPTION. For example, if an automobile, computer equipment, and a dwelling are all vandalized during a crime incident, there will be three property segment records. Each of the three will be coded with a TYPE OF PROPERTY LOSS of "vandalized." The three records will then be uniquely coded with a PROPERTY DESCRIPTION of "automobile," "computer equipment," and "dwelling," respectively.
The following offenses/offense categories can have property records associated with the incident:

Arson
Bribery
Burglary/Breaking and Entering
Counterfeiting/Forgery
Destruction/Damage/Vandalism of Property
Drug/Narcotic Offenses
Embezzlement
Extortion/Blackmail
Fraud Offenses
Gambling Offenses
Kidnapping/Abduction
Larceny, Theft Offenses
Motor Vehicle Theft
Robbery
Stolen Property Offenses

<strong>Victim Segment</strong>
Victim Segment (Level 04) - Victim data are collected to describe the victims involved in the incident. A separate set of victim data is recorded for each of the (up to 999) victims involved in the incident. There must be at least one set of victim data for each crime incident.
<strong>Offender Segment</strong>
Offender Segment (Level 05) - Offender data include characteristics (age, sex, and race) of each offender (up to 99) involved in a crime incident whether or not an arrest has been made. The object is to capture any information known to law enforcement concerning the offenders even though they may not have been identified. There are, of course, instances where no information about perpetrators is known.
<strong>Arrestee Segment</strong>
Arrestee Segment (Level 06) - Arrestee data are to be reported for all persons apprehended for the commission of Group A or Group B crimes, that is, all offenses except justifiable homicide (not a crime). It must be remembered that the object here is to collect data on persons arrested, not on charges lodged. For example, a person may be arrested on several charges in connection with the same incident. In this situation, only one set of arrestee data would be reported. However, if many incidents were cleared by a single arrest there would be only one arrest record. In such cases, the multiple arrestee segments indicator would have a value of "C" for one arrest and "M" for the rest. This allows the tallying of all clearances resulting from the arrest while at the same time indicating the actual number of persons arrested.
<strong>Group B Arrestee Segment</strong>
Group B Arrest Report Segment (Level 07) - Because of the different natures of Group A and B offenses, not all details required for Group A Incident Reports are requested for Group B Arrest Reports. Only arrestee data are required for Group B crimes. No other information need be supplied for Group B offenses.
<strong>Window Exceptional Clearance Segment</strong>
Window Segments reflect data in which the complete Group A Incident Report was not submitted to the FBI; rather, only a portion of the incident was submitted. A Window Segment record will be generated if the incident occurred prior to January 1 of the previous year or the incident occurred prior to when the agency began submitting NIBRS data to the FBI.
Window Exceptional Clearance Segment (Level W1) - This segment contains the same data elements as the Administrative Segment (01), plus up to 10 Group A offenses associated with the incident. In NIBRS, the submission of arrestee data automatically clears all offenses within an incident. Incidents can likewise be cleared by exceptional means when some element beyond law enforcement control precludes a physical arrest. Any exceptional clearance in an incident clears all related offenses. Exceptional clearances can be made and should be reported under one of the following five circumstances: 1) death of the offender, 2) prosecution denied, 3) in custody of other jurisdiction (includes extradition denied), 4) victim refused to cooperate, 5) juvenile/no custody. However, exceptional clearance of an incident does not necessarily result in a window exceptional clearance record. Such a record is only produced when an exceptional clearance occurs and a condition described in the previous paragraph also exists.
Example: A kidnapper holding a hostage killed himself when the building in which he barricaded himself was surrounded by police. The kidnapping is cleared exceptionally under "death of the offender." Even though the kidnapping is cleared exceptionally, no window exceptionally cleared record is generated. If, in addition, the kidnapper was also wanted for an armed robbery which occurred prior to January of the previous year, then the death of the offender would also exceptionally clear the armed robbery, and a window exceptionally cleared record would be generated for its clearance.
<strong>Window Recovered Property Segment</strong>
Window Recovered Property Segment (Level W3) - This segment contains the same data elements as the Property Segment (03) plus up to 10 Group A property offenses associated with the incident.
Example: Stolen property is recovered in the current year from a burglary that occurred prior to January 1 of the previous year. A Window Recovered Property Segment record will be generated.
<strong>Window Arrestee Segment</strong>
Window Arrests Segment (Level W6) - This segment contains the same data elements as the Arrestee Segment (06) plus window clearance flag and up to ten Group A offenses associated with the incident.
Example: An arrest is made by an agency that converted to NIBRS in the current year. The incident occurred in the previous year. A Window Arrest Segment record will be generated.
Additional Variable Information
<strong>Unit of Analysis</strong>
NIBRS contains data on different aspects of crime incidents, such as offenses, victims, offenders, arrestees, etc. These different aspects can be examined as different units of analysis. The phrase "unit of analysis" refers to the subject the researcher is examining. Statistical programs often refer to this as a case. The concept of unit of analysis is one aspect of NIBRS that makes the data challenging to work with. In NIBRS data the unit of analysis may correspond to any of the individual segment levels (offenses, property, victims, offenders, or arrestees), or it may be the crime incident itself. Users of NIBRS data should decide early in the research process what the unit of analysis will be. It is very easy to obtain erroneous results by using an incorrect unit of analysis.
<strong>Number of records</strong>
ICPSR has created separate files for each segment level (record type) on the NIBRS data. Each data file is sorted by ORI and incident number. On each file a variable (N RECORDS PER ORI-INCIDENT NUMBER) has been added that indicates the number of records that are within a block of records specified by ORI and incident number. This variable has a valid integer value for the first record in an incident, and it is system missing for subsequent records. For example, if the victim segment file contains three victim records for a particular ORI and incident number, these records would be shown as:
VARIABLES: N records per ORI-Incident Number
Victim record 1: 3
Victim record 2: (sysmis)
Victim record 3: (sysmis)
This variable is important when two or more files (segment levels) are being merged or restructured.
ICPSR performed additional processing tasks on these data. ICPSR checked to ensure records are uniquely identified as described above. All possible code values are documented for each variable. Each data file was sorted by ORI and incident number in ascending order.
<strong>Linkage Variables</strong>
To work with variables listed on two or more segment levels, the segment level files must be merged. The variables used to merge the files are the originating agency identifier (ORI) and the incident number. All segment levels except the batch header contain both the ORI and incident number. The batch header only contains the ORI. Within each segment level, these variables taken together uniquely identify a record:
Level - Variables
BH - Batch Header ORI
01 - Administrative ORI, Incident number
02 - Offense ORI, Incident number, UCR Offense code
03 - Property ORI, Incident number, Type of Property Loss, Property Description
04 - Victim ORI, Incident number, Victim sequence number 
05 - Offender ORI, Incident number, Offender sequence number 
06 - Arrestee ORI, Incident number, Arrestee sequence number 
W1 - Incident ORI, Incident number
W3 - Property ORI, Incident number, Property Description
W6 - Arrestee ORI, Incident number, Arrestee sequence number
<strong>Blanks and System Missing Data</strong>
Blank and system missing values were not recoded or labeled. These values often have a substantive meaning. Users of NIBRS data should refer to the variable documentation to determine the meaning of blanks and system missing values.
<strong>NIBRS Dates</strong>
The NIBRS dataset includes several date variables. A crime incident will be included in the 2021 dataset if any of these dates are in 2021. Other dates in the data may be for years other than 2021. For example, an arrest date of 2021 may correspond to an incident date of 2020. Both dates will be contained in the dataset.
<strong>Jurisdictional Reporting Rules</strong>
Throughout the Nation there are thousands of law enforcement agencies, some of which have overlapping jurisdictions. To be certain that data are not reported more than once by overlapping jurisdictions, the following
guidelines have been developed:

City law enforcement agencies report offenses that occur within their city boundaries.
County and state law enforcement agencies report offenses that take place in the county outside the limits of the city.
Federal agencies report offenses within their investigative jurisdictions if they are not being reported by a local/State law enforcement agency. (NOTE: At present there are no Federal agencies' data in the collection.)
When two or more Federal, State, or local agencies are involved in the investigation of the same offense and there is a written or oral agreement defining the roles of the investigating agencies, the agreement should designate which agency will report the offense.
When two or more Federal agencies are involved in the investigation of the same offense and there is no written or oral agreement defining their roles, the Federal agency having "lead" or "primary" investigative jurisdiction will report the incident. If there is uncertainty as to which is the "lead" or "primary" agency, the agencies should agree on which agency will report the offense.
Agencies report only those arrests made for offenses committed within their own boundaries/jurisdictions.
Likewise, the recovery of property is reported only by the agency that first reported it missing and/or stolen, regardless of whom or which agency recovered it.
description: NIBRS is an incident-based reporting system which means data are collected
on each single crime occurrence. NIBRS data are designed to be generated
as a by-product of local, State, and Federal automated records management
systems. Thus, an agency can build its own system to suit its individual
needs, including all the information required for administrative and
operational purposes. Only the data required by NIBRS are then reported to
the national UCR Program.
NIBRS collects data on each single incident and arrest within 28 offense
categories made up of 71 specific crimes called Group A offenses. For each of the offenses coming to the attention of law
enforcement, various facts about the crime are collected. In addition to
the Group A offenses, there are 10 Group B offense categories for which only arrest data are reported.
Central to NIBRS is the concept of a crime incident. An incident is defined
for NIBRS reporting purposes as one or more offenses committed by the same
offender, or group of offenders acting in concert, at the same time and
place. "Acting in concert" requires that the offenders actually commit or
assist in the commission of the crime(s). The offenders must be aware of,
and consent to, the commission of the crime(s); or even if nonconsenting,
their actions assist in the commission of the offense(s). This is important
because all of the offenders in an incident are considered to have
committed all of the offenses in the incident. If one or more of the
offenders did not act in concert, then there is more than one incident
involved.
The phrase "same time and place" means that the time interval between
the offenses and the distance between the locations where they occurred
were insignificant. Normally, the offenses must have occurred during an
unbroken period of time and at the same or adjoining location(s). However,
incidents can also consist of offenses which by their nature involve
continuing criminal activity by the same offender(s) at different times and
places, as long as the activity is deemed to constitute a single criminal
transaction.
The 2021 NIBRS dataset contains Group A incident records from 50 states, the District of Columbia, and Guam.
Some of these states report completely under NIBRS. In other states some law enforcement agencies report
under NIBRS and some report under the summary UCR system.
description: Datasets: 
DS0: Study-Level Files
DS1: Batch Header Segment
DS2: Administrative Segment
DS3: Offense Segment
DS4: Property Segment
DS5: Victim Segment
DS6: Offender Segment
DS7: Arrestee Segment
DS8: Group B Arrest Report Segment
DS9: Window Exceptionally Cleared Segment
DS10: Window Recovered Property Segment
DS11: Window Arrestee Segment
description: Law enforcement agencies in the United States
participating in the National Incident-Based Reporting System. Smallest Geographic Unit: city
description: computer-assisted self interview (CASI); self-enumerated questionnaireStarting with the 2012 data, some offense, location, bias motivation, race, and ethnicity codes have been added or modified to include recent Advisory Policy Board (APB) and Office of Management and Budget (OMB) policy mandates to the UCR Program related to Human Trafficking, Hate Crime, and Race and Ethnicity information.At the recommendation of the CJIS APB and with the approval of the FBI Director, the FBI UCR Program initiated the collection of rape data under a revised definition
and removed the term "forcible" from the offense name in 2013. The changes bring uniformity to the offense in both the Summary Reporting System (SRS) and the NIBRS by capturing data (1) without regard to gender, (2) including penetration of any bodily orifice by any object or body part, and (3) including offenses where physical force is not involved. As a result of this decision, the program renamed the NIBRS sex offenses - Forcible Rape to Rape, Forcible Sodomy to Sodomy, and Forcible Fondling to Fondling.At the recommendation of the Criminal Justice Information Services Advisory Policy Board, the UCR Program combined the offense categories of Sex Offenses [formerly Forcible] and Sex Offenses, Nonforcible. Beginning with the 2018 data, all offense types previously published in those two categories are now published in one category as Sex Offenses.Prior to the 2013 data, the Batch Header information was released as three segments. Due to the NIBRS data rapidly growing in size, the FBI has removed the B1, B2, and B3 sections. All information in these sections is now contained in a single batch header segment. Due to this change, ICPSR instituted new file numbering for the 2013 data and onward.
The Administrative Segment, formerly Part 4, is now Part 2.
The Offense Segment, formerly Part 5, is now Part 3.
The Property Segment, formerly Part 6, is now Part 4.
The Victim Segment, formerly Part 7, is now Part 5.
The Offender Segment, formerly Part 8, is now Part 6.
The Arrestee Segment, formerly Part 9, is now Part 7.
The Group B Arrestee Segment, formerly Part 10, is now Part 8.
The Window Exceptional Clearance Segment, formerly Part 11, is now Part 9.
The Window Recovered Property Segment, formerly Part 12, is now Part 10.
The Window Arrestee Segment, formerly Part 13, is now Part 11.Starting with the 2019 data, additional NIBRS offense codes for federal and tribal law enforcement agencies reporting only have been added.