The sample for the 2016 LEMAS 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. Some agencies in the 2016 LEAR did not have sworn staffing counts, which were excluded from the LEMAS universe. Agencies without the equivalent of one full-time sworn officer and sheriffs' offices without primary law enforcement jurisdiction in the counties they served were also excluded. After these removals, the LEMAS universe consisted of 12,416 local and county police departments, 3,012 sheriffs' offices and 49 primary state police departments.
Local police departments and sheriffs' offices were chosen for the 2016 LEMAS 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 represented all general purpose state and local law enforcement agencies in the U.S. with the equivalent of at least one full-time sworn officer 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.
The original 2016 LEMAS sample included 3,499 local, county and state law enforcement agencies. During the initial contact phase, it was determined that 28 departments were ineligible for the survey. Two agencies were serving special jurisdictions or with special enforcement responsibilities. Fourteen local police departments had closed and two had contracted their law enforcement services with another agency. Lastly, ten local police departments had less than one full-time equivalent sworn officer (i.e., only one part-time sworn officer). After removing out of scope cases, the final eligible sample size for the survey was 3,471 and included 1,045 self-representing (SR) agencies with 100 or more full-time equivalent sworn personnel and 2,426 non-self-representing (NSR) agencies employing fewer than 100 full-time equivalent sworn personnel.
The SR agencies included 638 local police departments, 358 sheriff's offices, and 49 state law enforcement agencies. The NSR local police departments and NSR sheriffs' offices were selected using a stratified random sample with cells based on the number of sworn personnel and agency type. Overall, the NSR local police department sample included 1,974 agencies and the NSR sheriffs' offices sample included 452 agencies.
Publicly funded state and local law enforcement agencies in the United States in 2016.
Submitted surveys were considered complete if at least 60% of the questionnaire was complete. A total of 2,779 agencies completed their LEMAS questionnaire for an over-all response rate of 80.1%. This included 879 SR agencies (84.1%) and 1,900 NSR agencies (78.3%). The response rate for local police departments was 81.7%; for sheriffs' offices it was 74.1%; and for primary state law enforcement agencies it was 89.8%. The final database includes completed responses from 2,135 local police departments, 600 sheriffs' offices, and 44 state agencies. The final database also includes partial data for the remaining 5 state police agencies. Four state police agencies submitted partial questionnaires during data quality follow-up efforts. One state police agency did not submit a questionnaire but data for item one was imputed (see Actions to Minimize Losses). Therefore, the total number of cases in the final dataset is 2,784.
An adjustment factor unique to each stratum was used to account for nonresponse. These nonresponse adjustments were multiplied by the base weight in order to create the final analytical weight for each stratum. For state law enforcement agencies, the final weight is 1.114. For SR sheriffs' offices it is 1.321 and for SR local police departments the final weight is 1.131. For NSR sheriffs' offices with 50-99 officers, the final weight is 7.408; with 25-49 officers, 7.392; with 10-24 officers, 8.811; with 5-9 officers, 7.667; with 2-4 officers, 9.125; and with 1 officer, 12.500. For NSR local police departments with 50-99 officers, the final weight is 7.185; with 25-49 officers, 6.914; with 10-24 officers, 6.978; with 5-9 officers, 7.305; with 2-4 officers, 8.134; and with 1 officer, 9.200.