About the Law Enforcement Agency Identifiers Crosswalk
Researchers have long been able to analyze crime and law enforcement data at the individual agency level and at the county level using data from the Federal Bureau of Investigation's Uniform Crime Reporting (UCR) Program data series. However, analyzing crime data at the intermediate level, the city or place, has been difficult, as has merging disparate data sources that have no common match keys. To facilitate the creation and analysis of place-level data and linking reported crime data with data from other sources, the Bureau of Justice Statistics (BJS) and the National Archive of Criminal Justice Data (NACJD) created the Law Enforcement Agency Identifiers Crosswalk (LEAIC).
The crosswalk file was designed to provide geographic and other identification information for each record included in the FBI's UCR files and Bureau of Justice Statistics' Census of State and Local Law Enforcement Agencies (CSLLEA). The LEAIC records contain common match keys for merging reported crime data and Census Bureau data. These linkage variables include the Originating Agency Identifier (ORI) code, Federal Information Processing Standards (FIPS) state, county and place codes, and Governments Integrated Directory government identifier codes. These variables make it possible for researchers to take police agency-level data, combine them with Bureau of the Census and BJS data, and perform place-level, jurisdiction-level, and government-level analyses.
Using the Resource Guide
The National Archive of Criminal Justice Data (NACJD), a part of the Inter-University Consortium for Political and Social Research (ICPSR) at the University of Michigan, designed this Resource Guide for World Wide Web users to learn about the Law Enforcement Agency Identifiers Crosswalk dataset and how to use it in conjunction with other resources.
With this guide, first time users or experienced analysts can:
- Find general information about law enforcement agencies and entities that report crime in the United States.
- Connect to other Law Enforcement Agency Identifiers related sites and data.
Law Enforcement Agency Identifiers Crosswalk Data
Criminal justice research may require merging disparate data sources that have no common match keys. The Law Enforcement Agency Identifiers Crosswalk (LEAIC) file facilitates linking reported crime data with socio-economic data. It does this by having a record for each law enforcement agency, law enforcement reporting entity, and beginning with the 2012 dataset access identifier for the National Crime Information Center (NCIC). Essentially, if an entity (law enforcement agency or section of a law enforcement agency) is capable of reporting crime information, it is included in the file. The LEAIC records contain common match keys for merging reported crime data and Census Bureau data. These linkage variables include the Originating Agency Identifier (ORI) code, Federal Information Processing Standards (FIPS) state, county and place codes, and Governments Integrated Directory government identifier codes.
File Structure
The Law Enforcement Agency Identifiers Crosswalk data is available from the ICPSR in logical record length (lrecl) format. SPSS, SAS, and Stata data definition statements are provided, giving the format and other information for each variable in the lrecl data file. The lrecl data file is constructed with a single logical record for each case.
Methodological Information
The Law Enforcement Agency Identifiers Crosswalk (LEAIC) file is primarily designed to apply geographic and government information to records representing law enforcement agencies.
The original motivation for creating the LEAIC file was to enable linking Uniform Crime Reporting (UCR) Program data, produced by the Federal Bureau of Investigation (FBI), with socio-economic data produced by the Census Bureau, e.g., to examine crime rates and poverty information at city level. A file such as the LEAIC is necessary to facilitate this type of research because of the different coding systems used by data sources. The FBI uses a unique coding system for states and counties. The codes are not used by other agencies. The Census Bureau typically uses Federal Information Processing Standards (FIPS) codes to geographically identify counties and states. In addition, the FIPS system has codes for places (county subdivisions, cities, census-designated places), but the UCR program does not. The LEAIC file "crosswalks" the UCR and FIPS state and county codes; it also adds FIPS place codes to law enforcement agency records. Consequently, a city-level analysis of crime and poverty could be done by merging UCR crime data to the LEAIC file by ORI code (contained in both the UCR and LEAIC files) and then merging the result to Census data using FIPS state and place codes (contained in both LEAIC and Census data).
While a file that does the above is very useful, additional utility is gained by including government information pertaining to the police agencies. Law enforcement agencies are formed under state, local and special jurisdiction legal authority. The LEAIC file contains the Census government identification code and government name pertaining to the law enforcement agencies. This information would allow an analysis of city-level crime information and government funding via Federal grants.
Most, but not all, law enforcement agencies report crime data to the FBI either directly or through state agencies. In addition to providing the crosswalk function described above, the LEAIC attempts to include all law enforcement agencies in the United States. The records in the LEAIC come from three main sources: the Census of State and Local Law Enforcement Agencies (most recently 2008); the FBI's Uniform Crime Reporting Program: Offenses Known and Clearances by Arrest, 2012; and an extract file supplied by the National Crime Information Center (NCIC). In addition a vendor-supplied list of police agencies was used for supplemental verification.
Records from the different source files represent different units of analysis. CSLLEA source records represent law enforcement agencies as defined by the CSLLEA. UCR source records may represent law enforcement agencies, similar to the CSLLEA, or law enforcement reporting entities contained within a larger related agency. For example the CSLLEA will contain one record for the MICHIGAN STATE POLICE. The UCR will contain a record for the MICHIGAN STATE POLICE overall and additional records for every state police post that has a separate ORI code. Consequently the UCR has more records than the CSLLEA. Records originating from the CSLLEA represent law enforcement entities, while records originating from the UCR represent both law enforcement agencies and law enforcement reporting entities.
The NCIC source file includes other types of records. These records represent reporting entities, both active and retired, and entities having access to the NCIC system. For example, records for the WASHINGTON [DC] METROPOLITAN POLICE DEPARTMENT are contained in all three source files (CSLLEA, UCR and NCIC). The NCIC file has an additional record for the [WASHINGTON, DC] METROPOLITAN POLICE DEPT RECRUITING DIVISION (ORI code DCMPD0100). A review of reported crime since 1985 shows no crime reported with this ORI. Most likely the ORI is/was used simply to access to the NCIC. This represents a third type of record in the LEAIC - access to the NCIC.
Records in the LEAIC can be thought of as representing up to three types of entities: "true" law enforcement agencies, law enforcement reporting entities, and access identifiers for the NCIC. Why include all? CSLLEA records are necessary for obvious reasons: They represent our best estimate of a census of all law enforcement agencies based on CSLLEA definitions. UCR records are necessary because crime is reported via the FBI's UCR program. A police agency may exist and not report through the UCR. Conversely, a reporting entity, such as a state police post, may report crime but not be specifically listed in the CSLLEA. Both records are included in the LEAIC. Excluding one of them would eliminate valuable data. The NCIC source records add substantially to the LEAIC because they include many records that are likely only access identifiers for the NCIC. Many of these records are for retired ORIs. However, we cannot be assured that the ORI will not be used to report crime. Also, if enough historical research were done, we may find that the retired ORIs were previously used to report crime. Thus the LEAIC file contains records that represent the union of three different sources where each source is somewhat different.
The main variables included in the file are FIPS state, county and place codes; UCR state and county codes; UCR ORI codes; agency name; and government codes and names. Population served information is included for UCR records (U_TPOP) and population for the government entity (LG_POPULATION).
Expansion of Scope
The 2012 dataset represents a new version of the LEAIC with an expanded scope. While the 2005 dataset was built on the 2000 dataset, which was built on the original 1996 crosswalk, the 2012 file was not built on previous versions. All types of information included in the three previous versions are in the 2012 version, however all variables were developed from original sources. This prevents any errors that may exist in previous versions from being carried over into the new version. In addition, he goal for the 2012 LEIAC was to not only facilitate linking data sources but also develop a law enforcement agency list that was both complete and accurate.
The PARTOF variable is used to indicate whether the law enforcement entity indicated by the record is a subsidiary entity to a larger entity. For example, the [WASHINGTON, DC] METROPOLITAN POLICE DEPT RECRUITING DIVISION is coded PARTOF=1. It is considered "part of" the WASHINGTON [DC] METROPOLITAN POLICE DEPARTMENT, which is coded PARTOF=0, meaning it is the main record representing the agency.
PARTOF is useful for subsetting the LEAIC file to main agencies. However, subsetting where PARTOF=0 could result in a file that does not include all records with crime reported via the UCR. For example, state police posts are coded PARTOF=1, meaning they are part of the main state police record, which is coded PARTOF=0. It is possible that the posts report crime. Subsetting would exclude them.
Errata
The items listed below will be incorporated into the next version of the crosswalk.
Error in Federal Information Processing Standards (FIPS) codes
- Ex. The FIPS place code 12345 for Springfield is incorrect. It should be 54321.
Other Law Enforcement Agency Identifiers Resources
Data
Law Enforcement Agency Identifiers Crosswalk Series
Uniform Crime Reporting Program Data Series
Directory of Law Enforcement Agencies Series
American Community Survey Data
Web Sites
Uniform Crime Reporting Program Resource Guide
National Crime Information Center
National Criminal Justice Reference Service
Publications
The link below will search the ICPSR citations database for citations of publications containing the phrase "law enforcement agency identifiers". Users can create their own searches or browse the citations database through our Publications Bibliography.