"As of December 31, 2020, more than 14,700 general-purpose law enforcement agencies in the United States employed about 708,000 full-time sworn officers and 348,000 full-time civilians. Local police departments accounted for about 80% (11,800) of the general-purpose agencies, employing nearly 67% (473,000) of full-time sworn personnel and 36% (126,000) of full-time civilian personnel (figure 1, table 1).1

"The total number of full-time personnel in local police departments increased nearly 13% from 1997 to 2020. The number of full-time sworn officers with general arrest powers also increased nearly 13%, from 420,000 in 1997 to 473,000 in 2020. The number of full-time civilians increased 24% from 1997 to 2007 (from 111,000 to 138,000) but then decreased nearly 9% (from 138,000 to 126,000) between 2007 and 2020."

Source

Sean E. Goodison, PhD. Local Police Departments Personnel, 2020. November 2022. NCJ305187. US Dept. of Justice, Bureau of Justice Statistics.