DOI: 10.3886/icpsr30763.v1
title: Uniform Crime Reporting Program Data: County-Level Detailed Arrest and Offense Data, 2009
title: Version 1

description: This data collection contains county-level counts of arrests and offenses for Part I offenses (murder, rape, robbery, aggravated assault, burglary, larceny, auto theft, and arson) and counts of arrests for Part II offenses (forgery, fraud, embezzlement, vandalism, weapons violations, sex offenses, drug and alcohol abuse violations, gambling, vagrancy, curfew violations, and runaways).
description: ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection: Standardized missing values.; Performed recodes and/or calculated derived variables.; Checked for undocumented or out-of-range codes..
description: Datasets: 
 
 DS0: Study-Level Files 
 DS1: Arrests, All Ages 
 DS2: Arrests, Adult 
 DS3: Arrests, Juveniles 
 DS4: Crimes Reported 
 DS5: Allocated Statewide Data for Arrests, All Ages 
 DS6: Allocated Statewide Data for Arrests, Adults 
 DS7: Allocated Statewide Data for Arrests, Juveniles 
 DS8: Allocated Statewide Data for Crimes Reported
description: Uniform Crime Reporting Program Data Series
description: self-enumerated questionnaire 
Two major changes to the Uniform Crime Reports (UCR) county-level files were implemented beginning with the 1994 data. A new imputation algorithm to adjust for incomplete reporting by individual law enforcement jurisdictions was adopted. Within each county, data from agencies reporting 3 to 11 months of information were weighted to yield 12-month equivalents. Data for agencies reporting less than three months of data were replaced with data estimated by rates calculated from agencies reporting 12 months of data located in the agency's geographic stratum within its state. Secondly, a new Coverage Indicator was created to provide users with a diagnostic measure of aggregated data quality in a particular county. Data from agencies reporting only statewide figures were allocated to the counties in the state in proportion to each county's share of the state population.
In the arrest files (Parts 1-3 and 5-7), data were estimated for agencies reporting zero months based on the procedures mentioned above. However, due to the structure of the data received from the Federal Bureau of Investigation (FBI), estimations could not be produced for agencies reporting zero months in the crimes reported files (Parts 4 and 8). Offense data for agencies reporting one or two months are estimated using the above procedures. Users are encouraged to refer to the codebook for more information.
No arrest data were provided for Florida. Limited arrest data were available for Illinois. Limited offense data were available for Alaska, Illinois, Mississippi, Montana, North Dakota, and South Dakota.
UCR program staff at the Federal Bureau of Investigation (FBI) were consulted in developing the new adjustment procedures. However, these UCR county-level files are not official FBI UCR releases and are being provided for research purposes only. Users with questions regarding these UCR county-level data files can contact the National Archive of Criminal Justice Data at ICPSR.
description: County law enforcement agencies in the United States. Smallest Geographic Unit: county