The detailed collection of crime statistics is an important tool for law enforcement and policymakers to use to analyze and address the social issue of crime. Understanding the contours of criminal conduct allows government to focus law enforcement resources appropriately. As a consequence, there is a wealth of statistical information available regarding crime in our nation and our state. However, the information must be used with caution and with an understanding of its limits.
When examining crime statistics it is important to understand what type of statistics they are, how they are collected and for what purpose they are designed. Broadly defined, these statistics can be separated into several categories. They are:
Reported crime. Most law enforcement agencies collect data on reported crimes. Since the 1930s the Federal Bureau of Investigation has established nationwide reporting standards and collects the data for publishing on an established schedule. The reporting is done through standard forms completed by each individual law enforcement agency. The FBI tracks two categories of offenses. Part I index crimes include seven types of major offenses broken into violent crime and property crime. Part I offenses are generally the offenses used consistently in the media in reporting crime trends. Part II index offenses track less serious offenses.
Although the FBI uniform crime report statistics are the most comprehensive statistics available, there are several inherent weaknesses that the user should be aware of. First, because they reflect only reported crime, they do not necessarily represent actual crime figures since not all crimes are reported to the police. As a consequence, in communities where residents are reluctant to report crimes to the police crime may appear lower than it is. Second, there may be differences between the laws of various states that make the reporting of certain crime categories inconsistent. For these reasons, the FBI cautions against using these statistics for comparison purposes, although this is a common practice in the media and even in government.
Despite the unavoidable problems with the statistics, they are enormously useful to analyze trends within reporting jurisdictions. For instance, the data will tell the reader definitively if crime reports are increasing or declining over time in a particular municipality, county or state.
Below are links to these FBI index reports from several levels of government:
FBI nationwide reports since 1995 can be found here. The site also provides substantial information regarding the history, process, and appropriate use of index crime report statistics.
Statistics for reported crimes in the state of Oregon are compiled by the Oregon State Police through their Law Enforcement Data System. The following link provides access to annual crime report statistics back to 1995 – click here. Another useful tool for accessing information on crime statistics in Oregon is the Oregon Criminal Justice Commission Statistical Analysis Center website found here. This site has a number of tools and graphs that will allow the reader to understand crime trends in the state and will allow comparisons between Oregon counties. These state statistics reveal generally that, compared to other states, Oregon has a low violent crime rate and a high property crime rate.
Portland Police Bureau statistics which reflect the crimes that agency has reported to the FBI can be found here. This electronic database only extends back to 2006. Archived data for crimes reported to the Portland Police Bureau from 1996 on can be found here.
Additionally, the Portland Police Bureau provides a useful crime mapping tool that allows the user to enter an address on a map of Portland to see what types of FBI Part I and Part II index crimes have been reported in specific locations on the map – click here.
International crime comparisons based on crime reports can be unreliable and suffer from the same problems, probably magnified, of inconsistent laws and reporting that exist in national index crime reports. However, the figures can be found at here. By selecting “Crime” in the category section a reader can obtain various country comparison charts about types of crimes that loosely resemble the FBI index crime reports. The site also contains other valuable information on country comparisons.
Victimization reports. Victimizations report studies are used to address some of the problems associated with uniform crime reports discussed above. As noted, crime report data can be unreliable when crime victims fail to report crimes to the police. This occurs often in communities where cultural or social attitudes affect residents’ relationship with the police and can have the unfortunate consequence of undercounting criminal activity. To counter this problem, researchers utilize victimization studies where scientific sampling, much like public opinion polling, is utilized to determine how many individuals in a particular area have been victimized by criminal conduct in a specific period of time, whether they reported it to the police or not. Unfortunately, victimization studies are extremely labor and resource intensive and therefore cannot be as comprehensive as crime report studies.
The federal Bureau of Justice Statistics conducts continuous victimization studies. Their main page on victimization appears here. A direct link to the most recent study (2010) is here.
International victimization studies are difficult to conduct. The only comprehensive long-term attempt to do so can be found in the International Crime Victims’ Survey, which has been collecting data since 1989. The latest survey is derived from figures collected in 2004-05 and can be found at in PDF form at the following link: click here.
For the most comprehensive study of the disposition of defendants within the criminal justice system, see the latest report on felony arrest processing in large American counties, produced by the federal Bureau of Justice Statistics. This study is one that is repeated periodically by this agency and reflects processing trends in state justice systems.