55 ILCS 5/3-8007
The Merit Commission shall have the duties, pursuant to recognized merit principles of public employment, of certification for employment and promotion, and, upon complaint of the sheriff or State's Attorney as limited in this Division, to discipline or discharge as the circumstances may warrant. All full time deputy sheriffs shall be under the jurisdiction of this Act and the county board may provide that other positions, including jail officers, as defined in "An Act to revise the law in relation to jails and jailers", approved March 3, 1874, as now or hereafter amended (repealed), shall be under the jurisdiction of the Commission. There may be exempted from coverage by resolution of the county board a "chief deputy" or "chief deputies" who shall be vested with all authorities granted to deputy sheriffs pursuant to Section 3-6015. "Chief Deputy" or "Chief Deputies" as used in this Section include the personal assistant or assistants of the sheriff whether titled "chief deputy", "undersheriff" , or "administrative assistant".
55 ILCS 5/3-8007