Court bailiff/civil process duties are provided by a court-appointed sheriff and his employees, none of whom have law enforcement powers.

The department is primarily responsible for law enforcement and investigations within unincorporated St. Louis County and contract municipalities, however, it has full police authority throughout the county, including its 88 municipalities which are also served by 58 local police departments, some of them very small.

In 2010, CALEA recognized the St. Louis County Police Department with it distinguished Tri-Arc Award.

[8] Witnesses testified that police department leadership had said that the sergeant would never be promoted because he was "way too out there with his gayness and he needed to tone it down if he wanted a white shirt."

As of 2023, the membership is: Board of Commissioners The Chief of Police serves as the senior sworn member of the SLCPD.

Kenneth Gregory is the tenth individual to hold the post and first African-American Chief in SLCPD History.

The Office of the Chief of Police has seven units or bureaus:[14] The Division of Patrol is commanded by Lieutenant Colonel Jim Schneider.

The SLCPD is divided into eight police precincts, three of which are contracted cities, Fenton, Wildwood, Jennings (5th, 6th and 8th).

Although the agency has full police authority of the sheriff in the entire county, including all municipalities, direct service population for the SLCPD is over 400,000 residents.

A majority of these 400,000 residents are located in South St. Louis County and Affton, both of which are unincorporated but heavily populated and suburban.

As a matter of policy, the department uses SWAT and police dogs to serve all felony warrants.

Metro Air Support, as of January 1, 2020, boasts 5 helicopters, 1 fixed wing airplane, 10 pilots, 1 flight instructor, and 2 mechanics.

Nearly 200 detectives provide county-wide services for the crimes of homicide, child abuse, St. Louis Regional Bomb and Arson Unit, domestic violence, sexual assault, fugitive apprehension, auto theft, burglary, fraud, robbery, drug abuse, and child exploitation.