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.
"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 time duration and at the same or adjoining location(s). However, incidents can also be comprised 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. Examples of crime incidents are included in the NIBRS codebook appendices.
Unit of Analysis
NIBRS contains data on many aspects of crime incidents, such as offenses, victims, offenders, arrestees, etc. These different aspects can be examined as different units of analysis. This is both a major benefit and a major complexity of NIBRS. With 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 must decide what the unit of analysis will be for a particular analysis. It is very easy to obtain erroneous results by incorrectly specifying the unit of analysis.
NIBRS Segment Levels
Throughout the NIBRS documentation the terms segment level and record type are used synonymously. The NIBRS segment levels are discussed below in the order that they appear in the "full" file as constructed by the FBI. There are thirteen separate segment levels.
Batch Header (BH) Segments 1, 2, and 3 - There are three batch header segments. They separate and identify individual police agencies by originating agency identifier (ORI). An individual police agency (ORI) will appear in the batch header segment once.
Group A Offenses
Each Group "A" Incident Report contains between four and six distinct records, each of which is referred to as a "Segment." The administrative, offense, victim, and offender segments are required for each Group A Incident Report. The property and arrestee segments may also be included. In addition, 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.
Administrative (01) Segment - 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 1 administrative segment record.
Offense (02) Segment - All offenses associated with a crime incident, up to 10, are listed on separate records. Care must be taken to identify all such offenses involved in an incident. 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. The NIBRS codebook has examples of reporting different offenses. Information on at least one offense must be included in each Group A Incident Report.
Property (03) Segment - 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.
Victim (04) Segment - 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.
Offender (05) Segment - Offender data include characteristics 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.
Arrestee (06) Segment - 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). The object here is to collect data on persons arrested, not on charges lodged. For example, the arrest of a single person in connection with several charges on an incident results in one arrest record.
Group B Offenses
Group B Arrest Report (07) Segment - 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.
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. The NIBRS codebook contains examples of data recorded in window segments.
Window Exceptional Clearance (W1) - Same data elements as Segment Level 01 (Administrative) plus up to 10 Group "A" offenses associated with the incident. In NIBRS, incidents can be cleared by exceptional means when some element beyond law enforcement control precludes a physical arrest. 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) Extradition Denied 4) Victim Refused to Cooperate 5) Juvenile/No Custody.
Window Recovered Property (W3) - Same data elements as Segment Level 03 (Property) plus up to 10 Group "A" property offenses associated with the incident.
Window Arrests (W6) - Same data elements as Segment Level 06 (Arrestee) plus window clearance flag and up to ten Group "A" offenses associated with the incident.
Offenses Covered by NIBRS
Group A offenses are the ones which NIBRS collects extensive data on. Specific definitions of each offense category are included in the NIBRS codebook. Below is a list of the Group A offenses:
- Assault Offenses
- Aggravated Assault
- Simple Assault
- Burglary/Breaking and Entering
- Destruction/Damage/Vandalism of Property
- Drug/Narcotic Offenses
- Drug/Narcotic Violations
- Drug Equipment Violations
- Fraud Offenses
- False Pretenses/Swindle/Confidence Game
- Credit Card/Automatic Teller Machine Fraud
- Welfare Fraud
- Wire Fraud
- Gambling Offenses
- Operating/Promoting/Assisting Gambling
- Gambling Equipment Violations
- Sports Tampering
- Homicide Offenses
- Murder and Nonnegligent Manslaughter
- Negligent Manslaughter
- Justifiable Homicide
- Larceny/Theft Offenses
- Theft from Building
- Theft from Coin-Operated Machine or Device
- Theft from Motor Vehicle
- Theft of Motor Vehicle Parts or Accessories
- All Other Larceny
- Motor Vehicle Theft
- Pornography/Obscene Material
- Prostitution Offenses
- Assisting or Promoting Prostitution
- Sex Offenses, Forcible
- Forcible Rape
- Forcible Sodomy
- Sexual Assault With An Object
- Forcible Fondling
- Sex Offenses, Nonforcible
- Stolen Property Offenses (Receiving, etc.)
- Weapon Law Violations
Group B offenses only have arrestee data recorded in NIBRS. Most Group B offenses only come to law enforcement attention when arrests are made.
- Bad Checks
- Curfew/Loitering/Vagrancy Violations
- Disorderly Conduct
- Driving Under the Influence
- Family Offenses, Nonviolent
- Liquor Law Violations
- Peeping Tom
- Trespass of Real Property
- All Other Offenses