<P> The 2012 Bureau of Justice Statistics' Census of State and Local Law Enforcement Agencies (CSLLEA), found there were 17,985 state and local law enforcement agencies employing at least one full - time officer or the equivalent in part - time officers . </P> <P> In 2008, state and local law enforcement agencies employed more than 1.1 million people on a full - time basis, including about 765,000 sworn personnel (defined as those with general arrest powers). Agencies also employed approximately 100,000 part - time employees, including 44,000 sworn officers . </P> <P> From 2004 to 2008, overall full - time employment by state and local law enforcement agencies nationwide increased by about 57,000 (or 5.3%). Sworn personnel increased by about 33,000 (4.6%), and nonsworn employees by about 24,000 (6.9%). From 2004 to 2008, the number of full - time sworn personnel per 100,000 U.S. residents increased from 250 to 251 . From 1992 to 2008, the growth rate for civilian personnel was more than double that of sworn personnel . </P> <P> Local police departments were the largest employer of sworn personnel, accounting for 60% of the total . Sheriffs' offices were next, accounting for 24% . About half (49%) of all agencies employed fewer than 10 full - time officers . Nearly two - thirds (64%) of sworn personnel worked for agencies that employed 100 or more officers . </P>

History of law enforcement in the united states