Uniform Crime Reporting Program Data: Police Employee (LEOKA) Data, 2012 (ICPSR 35020)

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United States Department of Justice. Federal Bureau of Investigation



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The Uniform Crime Reporting Program Data, Police Employee Data, 2012 file contains monthly data on felonious or accidental killings and assaults upon United States law enforcement officers acting in the line of duty. The Federal Bureau of Investigation (FBI) assembled the data and processed them from UCR Master Police Employee (LEOKA) data tapes. Each agency record in the file includes the following summary variables: state code, population group code, geographic division, Metropolitan Statistical Area code, and agency name. These variables afford considerable flexibility in creating subsets or aggregations of the data. Since 1930, the Federal Bureau of Investigation has compiled the Uniform Crime Reports (UCR) to serve as a periodic nationwide assessment of reported crimes not available elsewhere in the criminal justice system. Each year, this information is reported in four types of files: (1) Offenses Known and Clearances by Arrest, (2) Property Stolen and Recovered, (3) Supplementary Homicide Reports (SHR), and (4) Police Employee (LEOKA) Data. The Police Employee (LEOKA) Data provide information about law enforcement officers killed or assaulted (hence the acronym, LEOKA) in the line of duty. The variables created from the LEOKA forms provide in-depth information on the circumstances surrounding killings or assaults, including type of call answered, type of weapon used, and type of patrol the officers were on.

United States Department of Justice. Federal Bureau of Investigation. Uniform Crime Reporting Program Data: Police Employee (LEOKA) Data, 2012. Inter-university Consortium for Political and Social Research [distributor], 2014-04-16. https://doi.org/10.3886/ICPSR35020.v1

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United States Department of Justice. Office of Justice Programs. Bureau of Justice Statistics

states, counties, cities

Inter-university Consortium for Political and Social Research
  1. Starting with the year 1998, each of the four parts of the UCR data collection archived by ICPSR is released as a separate study under its own study number. The Police Employee data for the years 1975-1997 can be found in UNIFORM CRIME REPORTING PROGRAM DATA [UNITED STATES]: 1975-1997 (ICPSR 9028).


UCR Program contributors compile and submit their crime data by one of two means: either directly to the FBI or through their state UCR Programs. State UCR programs frequently impose mandatory reporting requirements which have been effective in increasing both the number of reporting agencies as well as the number and accuracy of each participating agency's reports.

The LEOKA dataset contains information collected through two UCR Program reporting forms: the annual "Law Enforcement Employees Report" and the monthly "Law Enforcement Officers Killed or Assaulted" (LEOKA) report. Together they represent the FBI's effort to produce a comprehensive dataset of assaults on police officers and, more generally, of "police strength" (the amount of resources devoted to policing as measured by the number of persons employed in law enforcement agencies).

The Law Enforcement Employees Report, a form sent to police agencies throughout the country by the FBI once a year, asked for a count of employees on the payroll of each agency as of October 31. The number of full-time law enforcement employees, officers and civilians, was requested by this form. Officers are defined as full-time, sworn personnel with full arrest powers including the chief, sheriff, or other head of the department. Persons performing guard or protection duties, such as school crossing guards, special officers, and merchant police, who were not paid from law enforcement funds were not included. Civilian employees include persons such as clerks, radio dispatchers, parking enforcement personnel, stenographers, mechanics, etc., who were full-time employees of the agency. Employees, both officers and civilians, who were on leave with pay also were included.

Information from the LEOKA report constitutes the second and largest portion of the dataset. For any month in which felonious or accidental killings and/or nonfatal assaults on law enforcement officers acting in the line of duty were reported on the UCR Return A form, a LEOKA form was to have been submitted to provide additional information regarding the attack. (See ICPSR 4124, UNIFORM CRIME REPORTING DATA [UNITED STATES]: OFFENSES KNOWN AND CLEARANCES BY ARREST, 2003 for a description of Return A). Monthly variables are coded zero for months in which no assaults occurred.

The LEOKA form gathered data on assaults that resulted in serious injury or in which a weapon was used that could have caused serious injury or death. Other assaults not resulting in injury were included, if they involved more than verbal abuse or minor resistance during the course of an arrest. Details are available on the number and type of patrols and shift assignments, the number of injury and non-injury assaults by type of weapon, and the number of weapon-specific assaults by situation type. These situations include disturbance calls, burglaries, robberies, other arrests attempted, civil disorders, custody of prisoners, suspicious persons, ambushes without warning, mentally deranged persons, traffic pursuits and stops, and all other circumstances. For each of these categories, the number of police assaults cleared by arrest (or other exceptional means) are also included. The final group of variables are assault counts by time of occurrence (in two-hour increments, e.g., the number of assaults occurring between 12:01am and 2:00am, 2:01am and 4:00am, and so on).

Law enforcement officers killed or assaulted as reported by law enforcement agencies.

law enforcement agencies


2018-02-15 The citation of this study may have changed due to the new version control system that has been implemented. The previous citation was:
  • United States Department of Justice. Federal Bureau of Investigation. Uniform Crime Reporting Program Data: Police Employee (LEOKA) Data, 2012. ICPSR35020-v1. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2014-04-16. http://doi.org/10.3886/ICPSR35020.v1

2014-04-16 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:

  • Performed consistency checks.
  • Checked for undocumented or out-of-range codes.


  • The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.

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This dataset is maintained and distributed by the National Archive of Criminal Justice Data (NACJD), the criminal justice archive within ICPSR. NACJD is primarily sponsored by three agencies within the U.S. Department of Justice: the Bureau of Justice Statistics, the National Institute of Justice, and the Office of Juvenile Justice and Delinquency Prevention.