Crime Statistics

Criminologists who study crime, those who work in the field of criminal justice, politicians, and the public all have an interest in crime statistics. Criminologists use crime data to test theories about crime; criminal justice professionals use crime [Page 152]statistics to help predict what is coming their way and to help measure how well they are doing; politicians use crime statistics as evidence to enact policies; and the public is often alerted when crime statistics indicate crime waves or increases in some crime that the media find alarming. This entry reviews some of the major data sources used by those who study crime and work in the criminal justice system to produce crime statistics in the United States. A few data sets that help one get around “the dark figure of crime” are also discussed. Finally, sources for crime statistics in other countries and national data are discussed, followed by a brief review of the trends in crime around the turn of the 21st century in the United States, Canada, and elsewhere.

The most well-known source of data for crime statistics in the United States is the Uniform Crime Reports (UCR), which have been collected by the Federal Bureau of Investigation (FBI) since the early 1930s. The FBI's UCR statistics are published each year in Crime in the United States. The data collected are divided into two parts. Part I of the UCR has traditionally been referred to as the Crime Index, and it has been used as a barometer for crime in the United States. Data on eight crimes that are reported to the police or otherwise come to the attention of police are included in Part I or the Crime Index. Four of these crimes are considered violent because there is interaction between the offender and the victim with injury or the potential for injury: murder, aggravated assault, rape, and robbery. The remaining four in the index are property crimes, or those in which property is taken or destroyed: arson, larceny/theft, burglary, and motor vehicle theft.

Part II of the UCR includes data on all arrests made by the police across the United States and thus, Part II includes many more categories of crime than Part I. Some of the crimes included in Part II are simple assaults, forgery, sex crimes, prostitution, liquor law violations, disturbing the peace, and driving under the influence of alcohol or drug or narcotic. While there are some issues with the accuracy of the UCR data (as discussed in the entry on the UCR in this encyclopedia), the UCR offer almost complete coverage of the United States, and thus, the statistics provided by this data source are usually a good indicator of the trends in crime for the United States.

One thing that some criminologists find lacking in the UCR is detail. For the most part, the UCR just allow simple counts of crimes and little detail on victim and offender characteristics. There are, however, two data sets also collected by the FBI that give more detail on both offenders and victims. First, the FBI has been collecting the Supplemental Homicide Reports (SHR) since 1961. The SHR contains the most detailed, comprehensive, and reliable data on homicide across the United States. With this data, one can learn about the age, sex, and race of victims and offenders as well as the relationship between the victim and the offender, the type of weapon used, and the circumstance or proximate cause of the homicide incident.

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