Traditionally, crime reports consist of monthly counts of offenses and arrests for certain offense categories. State and local agencies report these summary data to the FBIs Uniform Crime Reporting (UCR) Program. These reports provide little information about the characteristics of crimes, victims, offenders or arrests. Use of these data in research and policy analysis is severely limited.

Collecting data about each incident overcomes many of these deficiencies. Along with the Summary UCR, the FBI has been collecting incident-based data on homicide through the Supplementary Homicide Reports for many years. Several States and localities implemented incident-based systems for collecting crime statistics in the 1970's.

The FBI recognized the need for additional information about crime that was comparable across jurisdictions and included more types of crime. After much study, the FBI launched the National Incident-Based Reporting System (NIBRS). Compared to Summary UCR, NIBRS collects more details on more categories of crime, including concurrent offenses, weapons, injury, location, property loss and characteristics of the victims, offenders and arrestees. Because State and local agencies also collect details outside the scope of NIBRS, such as incident addresses, NIBRS is usually a subset of State and local incident-based data.

NIBRS increases what we know about crime due to:

• Expansion of the number of offense categories included.
• Detail on individual crime incidents (offenses, offenders, victims, property, and arrests)
• Linkage between arrests and clearances to specific incidents or offenses.
• Inclusion of all offenses in an incident rather than only the most serious offense.
• The ability to distinguish between attempted and completed crimes.
• Linkages between offense, offender, victim, property, and arrestee variables which permits examination of interrelationships.

The UCR Program is being rapidly expanded with NIBRS. In 1991 South Carolina and North Dakota, the first certified states, began submitting data following FBI standards and definitions. As of 2001, more than 3,725 agencies across 21 States submit NIBRS data. In seven of these states 90 to 100 percent of the population is covered by NIBRS reporting. (See the current level of UCR and NIBRS participation by State as of December, 2003.)

While national-level data are not currently available, analysts and researchers will find a wealth of information about crime in the NIBRS data that is available. The data, along with descriptive information on its structure and use, can be freely obtained online from the National Archive of Criminal Justice Data, a BJS sponsored program (See Resources for analyzing NIBRS data below). Further examples of the type of information that can be developed from incident-based systems are presented under publications.