Department of Justice The Nation's two crime measures

The U.S. Department of Justice administers two statistical programs problem. Because the UCR and NCVS programs are conducted for to measure the magnitude, nature, and impact of crime in the different purposes, use different methods, and focus on somewhat Nation: the Uniform Crime Reporting (UCR) Program and the different aspects of crime, the information they produce together National Crime Victimization Survey (NCVS). Each program provides a more comprehensive panorama of the Nation's crime produces valuable information about aspects of the Nation's crime problem than either could produce alone.

Uniform Crime Reports National Crime Victimization Survey Federal Bureau of Investigation (FBI) Bureau of Justice Statistics (BJS)

The FBI's UCR program, which among neighboring jurisdictions The Bureau of Justice Statistics enforcement, and it summarizes began in 1929, collects informa- and among those with similar NCVS program, which began in the reasons that victims give for tion on the following crimes populations and other common 1973, provides a detailed pic- reporting or not reporting. reported to law enforcement characteristics. ture of crime incidents, victims, authorities: homicide, forcible and trends. After a substantial The survey provides information rape, robbery, aggravated UCR findings for each calendar period of research, in 1993 the about victims (age, sex, race, assault, burglary, larceny-theft, year are published in a survey completed an intensive ethnicity, marital status, income, motor vehicle theft, and arson. preliminary release in the methodological redesign. The and educational level), Arrests are reported for 21 spring, followed by a detailed redesign was undertaken to offenders (sex, race, estimated additional crime categories. annual report, Crime in the improve the questions used to age, and victim-offender United States, issued in the uncover crime, update the sur- relationship), and the crimes The UCR data are compiled following calendar year. In vey methods, and broaden the (time and place of occurrence, from monthly law enforcement addition to crime counts and scope of crimes measured. The use of weapons, nature of reports or individual crime trends, this report includes data redesigned survey collects injury, and economic incident records transmitted on crimes cleared, persons detailed information on the consequences). Questions also directly to the FBI or to arrested (age, sex, and race), frequency and nature of the cover the experiences of victims centralized state agencies that law enforcement personnel crimes of rape, sexual assault, with the criminal justice system, then report to the FBI. Each (including the number of sworn personal robbery, aggravated self-protective measures used report submitted to the UCR officers killed or assaulted), and and simple assault, household by victims, and possible Program is examined thoroughly the characteristics of homicides burglary, theft, and motor substance abuse by offenders. for reasonableness, accuracy, (including age, sex, and race of vehicle theft. It does not Supplements are added and deviations that may indicate victims and offenders, victim- measure homicide or periodically to the survey to errors. Large variations in crime offender relationships, weapons commercial crimes (such as obtain detailed information on levels may indicate modified used, and circumstances burglaries of stores). topics like school crime. records procedures, incomplete surrounding the homicides). reporting, or changes in a Other special reports are also Two times a year, U.S. Census The first data from the jurisdiction's boundaries. To available from the UCR Bureau personnel interview redesigned NCVS were identify any unusual fluctuations Program. household members in a published in a BJS bulletin in in an agency's crime counts, nationally representative sample June 1995. BJS publication of monthly reports are compared Following a 5-year redesign of approximately 42,000 NCVS data includes Criminal with previous submissions of the effort, the UCR Program is households (about 75,000 Victimization in the United agency and with those for currently being converted to the people). Approximately 150,000 States, an annual report that similar agencies. more comprehensive and interviews of persons age 12 or covers the broad range of detailed National older are conducted annually. detailed information collected by In 2003, law enforcement Incident-Based Reporting Households stay in the sample the NCVS. BJS publishes agencies active in the UCR System (NIBRS). NIBRS will for three years. New detailed reports on topics such Program represented provide detailed information households are rotated into the as crime against women, urban approximately 291 million U.S. about each criminal incident in sample on an ongoing basis. crime, and gun use in crime. inhabitants — 93.0 percent of 22 broad categories of offenses. The NCVS and UCR data files the total population. The NCVS collects information are archived at the National on crimes suffered by individ- Archive of Criminal Justice Data The UCR Program provides uals and households, whether at the University of Michigan to crime counts for the Nation as a or not those crimes were enable researchers to perform whole, as well as for regions, reported to law enforcement. It independent analysis. states, counties, cities, and estimates the proportion of each towns. This permits studies crime type reported to law

October 2004, NCJ 122705 Comparing UCR and NCVS

Because the NCVS was Third, because of methodology, counts of offenses reported by been reported to police with designed to complement the the NCVS and UCR definitions law enforcement jurisdictions. In UCR statistics. UCR program, the two of some crimes differ. For some circumstances, UCR data programs share many example, the UCR defines are estimated for nonpartici- For most types of crimes similarities. As much as their burglary as the unlawful entry or pating jurisdictions or those measured by both the UCR and different collection methods attempted entry of a structure to reporting partial data. NCVS, analysts familiar with the permit, the two measure the commit a felony or theft. The programs can exclude from same subset of serious crimes, NCVS, not wanting to ask Each program has unique analysis those aspects of crime defined alike. Both programs victims to ascertain offender strengths. The UCR provides not common to both. Resulting cover rape, robbery, aggravated motives, defines burglary as the a measure of the number of long-term trend lines can be assault, burglary, theft, and entry or attempted entry crimes reported to law enforce- brought into close concordance. motor vehicle theft. Rape, of a residence by a person who ment agencies throughout the The impact of such adjustments robbery, theft, and motor vehicle had no right to be there. country. The UCR's is most striking for robbery, theft are defined virtually Supplemental Homicide Reports burglary, and motor vehicle identically by both the UCR and Fourth, for property crimes provide the most reliable, timely theft, whose definitions most NCVS. (While rape is defined (burglary, theft and motor data on the extent and nature of closely coincide. analogously, the UCR Crime vehicle theft), the two programs homicides in the Nation. The Index measures the crime calculate crime rates using NCVS is the primary source of With robbery, annual against women only, and the different bases. The UCR rates information on the character- victimization rates based only NCVS measures it against both for these crimes are per-capita istics of criminal victimization on NCVS robberies reported to sexes.) (number of crimes per 100,000 and on the number and types of the police are possible. It is also persons), whereas the NCVS crimes not reported to law possible to remove from There are also significant rates for these crimes are enforcement authorities. analysis UCR robberies of differences between the two per-household (number of commercial establishments programs. First, the two crimes per 1,000 households). By understanding the strengths such as gas stations, programs were created to serve Because the number of house- and limitations of each program, convenience stores, and banks. different purposes. The UCR holds may not grow at the same it is possible to use the UCR When the resulting NCVS Program's primary objective is rate each year as the total and NCVS to achieve a greater police-reported robbery rates to provide a reliable set of population, trend data for rates understanding of crime trends are compared to UCR criminal justice statistics for law of property crimes measured by and the nature of crime in the non-commercial robbery rates, enforcement administration, the two programs may not be United States. For example, the results reveal closely operation, and management. comparable. changes in police procedures, corresponding long-term trends. The NCVS was established to shifting attitudes towards crime provide previously unavailable In addition, some differences in and police, and other societal information about crime the data from the two programs changes can affect the extent to (including crime not reported to may result from sampling which people report and law police), victims, and offenders. variation in the NCVS and from enforcement agencies record estimating for nonresponse in crime. NCVS and UCR data can Second, the two programs the UCR. The NCVS estimates be used in concert to explore measure an overlapping but are derived from interviewing a why trends in reported and non- identical set of crimes. The sample and are therefore police-recorded crime may NCVS includes crimes both subject to a margin of error. differ. reported and not reported to law Rigorous statistical methods are enforcement. The NCVS used to calculate confidence Apparent discrepancies excludes, but the UCR includes, intervals around all survey between statistics from the two homicide, arson, commercial estimates. Trend data in NCVS programs can usually be crimes, and crimes against reports are described as accounted for by their children under age 12. The UCR genuine only if there is at least a definitional and procedural captures crimes reported to law 90% certainty that the measured differences or resolved by enforcement, but it excludes changes are not the result of comparing NCVS sampling sexual assaults and simple sampling variation. The UCR variations (confidence intervals) assaults from the Crime Index. data are based on the actual of those crimes said to have

October 2004, NCJ 122705