Uniform Crime Reports (UCR)
The vast majority of crime statistics used in the United States comes from the UCR. In 1929, the FBI started collecting information from local law enforcement agencies about the number of crimes that occurred in each jurisdiction. In the 1920s, as the scientific study of policing began as a field, the Association of Police Chiefs and the Social Science research council wanted to have a clear set of national crime statistics around major crimes (Part I Offenses—murder, rape, aggravated assault, robbery, larceny, and motor vehicle theft) to allow for comparison across jurisdictions. A jurisdiction is an area over which a particular body has legal authority. Examples are cities, counties, states, and nations. Congress passed a law (28 U.S.C. § 534) in 1930 to charge the FBI with this task, creating the Uniform Crime Report. From 1935 through the 1980s, the FBI was the primary place to get crime statistics and still runs the UCR today.
The UCR depends on local police agencies in order to compile crime statistics. Approximately 18,000 city, university and college, county, state, tribal, and federal law enforcement agencies contribute their data to the UCR annually (Bureau of Justice Statistics [BJS], 2017). Thus, the UCR is a measure of crimes that are detected and reported by the police. In the 1980s, the UCR went through a revision to make the data more accurate and easier for agencies to report. The result of the revisions was the National Incident-Based Reporting System (NIBRS), which is now collecting information on administrative, offense, victim, property, offender, and arrestees using a standardize reporting form. This new system makes the UCR a more complete report.
Although the UCR is a decent measure of the crime we know about, many crime events are never reported to the police, meaning that the UCR is underreporting crime. The exception is murder because the vast majority of murders are known to the police. Other types of crimes, especially rape and sexual assault, have very low
levels of reporting to the police. This was discovered through victimization surveys, like the National Crime Victims Survey discussed next. In addition, because not all agencies include all crime, the FBI creates a estimation of the amount of crime in a particular area. Although there are issues with the UCR, it is still a good source of information to understand crime in an area. In addition to the FBI, several other agencies collect various types of data. See the following table for information on these other agencies.