Analyst Toolbox

The Differences Between UCR and NIBRS

Product: UCR/NIBRS

Analysts often encounter statistics or data in Uniform Crime Report (UCR) and NIBRS (National Incident-Based Reporting System) format. What is the difference between the two?

Both involve agencies submitting reports to the FBI, but in the UCR program the agencies report summary data—totals and sums. For instance, in 2004 the agency might report that it had:

Murders: 12
Rapes: 83
Robberies: 327

And so on. In the NIBRS system, in contrast, agencies report data about each individual incident:

2004-13340 09/15/2004 13:15 Murder Parking Lot Handgun
2004-27255 10/12/2004 20:50 Robbery Liquor Store Knife

There are dozens of data fields involving modus operandi, victim, offender, drugs, vehicles, and property that agencies must report on each incident. Only agencies with compliant records management systems and good data-quality-control processes can do it.

NIBRS collects data about more types of incidents than UCR. UCR’s “Part 1” crime category includes eight offenses, while NIBRS’S “Group A” category includes 46 offenses in 22 categories.

Finally, UCR follows a “hierarchy” rule for each incident in which only the most serious offense is reported, while in the NIBRS system every individual offense is reported. Assume a drunken bar patron attacks another customer with a stool (aggravated assault), throws the same stool through a window (vandalism), and leaves without paying for his drinks (larceny). Under the UCR program, on the aggravated assault would “count,” whereas under the NIBRS system, each individual offense is reported. However, NIBRS also recognizes the concept of “lesser included offenses”—since almost every burglary involves a larceny, for instance, it’s not necessary to report the latter with the former.

For more information, see http://www.fbi.gov/hq/cjisd/ucr.htm

Author: Christopher Bruce
Updated 3/6/2005

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