Law Enforcement Management and Administrative Statistics Body-Worn Camera Supplement (LEMAS-BWCS), 2016 (ICPSR 37302)

Time Period(s) View help for Time Period(s)

Study Purpose View help for Study Purpose

Due to the breadth of the Law Enforcement Management and Administrative Statistics (LEMAS) survey, detailed analysis of any specific law enforcement topic cannot be done with the LEMAS core. The LEMAS supplements are designed to fill this void by allowing for a more comprehensive examination on a key topic in law enforcement and are administered in between core years. The 2016 LEMAS Body- Worn Camera Supplement (LEMAS-BWCS) is the first supplement administered under the new structure.

Study Design View help for Study Design

Data were primarily collected through two different modes. Agencies had the choice to respond via web or mail in a paper survey. Additional data was captured through phone interviews with an abbreviated list of questions from the survey. Among the responding agencies, 86% completed via web, 12% via mail, and 2% by combination of web and phone.

All departments, regardless of having obtained body-worn cameras (BWCs), were asked to complete the LEMAS-BWCS. Items 1-10 and 67-72 were asked of all respondents. Items 11-60 were asked among those agencies that reported having acquired BWCs, while items 61-66 were asked for agencies that had not acquired body-worn cameras (BWCs). For the 3,928 agencies completing the survey, overall item nonresponse rates due to omission or invalid data were less than 2% for the majority of items. Respondents missing data for a particular item were not removed from the denominator for analyses in the report, Body-Worn Cameras in Law Enforcement Agencies, 2016 (NCJ 251775).

Imputation was used only on the number of full-time sworn officers. Cold-deck imputation was implemented using the value from the Law Enforcement Agency Roster (LEAR) frame. Minor editing was completed for BWC acquisition based on subsequent questions (i.e., an agency marking had not acquired but answered the questions on acquisition confirming they had in fact acquired BWCs).

Sample View help for Sample

The sample for the 2016 LEMAS-BWCS was derived from the 2016 Law Enforcement Agency Roster (LEAR) database. The LEAR was originally built from a variety of sources including, but not limited to, the 2008 and 2014 Census of State and Local Law Enforcement Agencies (CSLLEA) and the 2013 LEMAS Survey. The 2016 LEAR contains a census of 15,810 general purpose law enforcement agencies, including 12,695 local and county police departments, 3,066 sheriffs' offices and 49 primary state police departments.

Local police departments and sheriffs' offices were chosen for the 2016 LEMAS-BWCS using a stratified sample design based on number of full- and part-time sworn officers (part-time officers were counted as 0.5 full-time equivalents) and agency type. The sample was designed to be representative of all general purpose state and local law enforcement agencies in the United States, with separate samples drawn of local police departments and sheriffs' offices. All 49 primary state law enforcement agencies (state police and highway patrol) and all local departments and sheriffs' offices with 100 or more full-time sworn officers were included. Agencies serving special jurisdictions (such as schools, airports, or parks), or with special enforcement responsibilities (such as conservation laws or alcohol laws), were considered out of scope for the LEMAS-BWCS.

The original 2016 LEMAS-BWCS sample included 5,063 local, county and state law enforcement agencies. During the data collection phase, it was determined that 56 agencies did not engage in primary law enforcement activities, 13 agencies had closed, 7 had one part-time sworn officer (a minimum of the equivalent of one full-time officer was required for inclusion), 3 were temporarily without sworn staff, 7 were part of another agency or contracted services and 1 was a duplicate agency. The final sample size was 4,976 and included 1,048 self-representing (SR) agencies with 100 or more sworn personnel and 3,928 nonself-representing (NSR) agencies employing fewer than 100 sworn personnel.

The SR agencies included 640 local and county police departments, 359 sheriffs' offices, and 49 state law enforcement agencies. The NSR local police agencies and NSR sheriffs' agencies were selected using a stratified random sample based on the number of sworn personnel and agency type. The total NSR local police sample included 3,067 agencies and the NSR sheriffs' agencies sample included 861 agencies.

Time Method View help for Time Method

Universe View help for Universe

Publicly funded state and local law enforcement agencies in the United States in 2016

Unit(s) of Observation View help for Unit(s) of Observation

Data Type(s) View help for Data Type(s)

Mode of Data Collection View help for Mode of Data Collection

Description of Variables View help for Description of Variables

Variables in this study include information on individual law enforcement agencies, the agencies' use of body-worn cameras and other recording equipment, and policies and procedures covering body-worn cameras and other recording equipment.

Response Rates View help for Response Rates

Of the 4,976 eligible agencies that received the 2016 LEMAS-BWCS, 3,928 agencies completed the survey, for a response rate of 79%. By size, the response rate for local police departments ranged from 92% for SR agencies to 62% for agencies with 1 officer. For sheriffs' offices, the response rate ranged from 83% for SR agencies to 50% for agencies with 1 officer. The response rate for primary state police agencies was approximately 90%.

Since the overall response rate was less than 80%, a non-response bias analysis was conducted. Effect sizes were calculated across agency type only, size only, size and type combined, and census region. Frame data were used for both respondents and non-respondents. The effect size compares sample members to respondents to detect if there is large deviation. Generally, effect sizes less than 0.2 are considered small and do not indicate concern for nonresponse bias. All four effect sizes were smaller than 0.2, with the combination of size and type having the largest calculated effect size of 0.1.

An adjustment factor unique to each stratum was used to account for non-response and ineligible agencies. Five primary state police agencies did not complete the LEMAS-BWCS. Two state agencies submitted a LEMAS-BWCS questionnaire that was not complete but were confirmed they had not acquired BWCs. The other three state agencies that did not submit a LEMAS-BWCS completed the 2016 LEMAS core survey and indicated that they had 0 BWCs. Therefore, the 13 state agencies that reported having BWCs represents the census of state police agencies with BWCs and did not require a nonresponse adjustment. The nonresponse adjustment was calculated for state police agencies without BWCs and a final weight of 1.161 is applied to items that were asked only of agencies without BWCs.

Original Release Date View help for Original Release Date

2019-06-20

Version History View help for Version History

Weight View help for Weight

The base weight for the SR departments was 1.000. The 6 remaining strata for local police departments and their corresponding base weights were 50 to 99 officers, 3.756; 25 to 49 officers, 3.745; 10 to 24 officers, 3.746; 5 to 9 officers, 3.748; 2 to 4 officers, 3.748, and 1 officer, 3.756. For sheriffs' offices the corresponding base weights were 50 to 99 officers, 3.076; 25 to 49 officers, 3.068; 10 to 24 officers, 3.052; 5 to 9 officers, 3.040; 2 to 4 officers, 3.085, and 1 officer, 2.889.