LANSING, Mich. (WLNS) — Clinton County Sheriff Officials confirm there is a separate investigation of former city of DeWitt Clerk/Treasurer Lisa Grysen from one being conducted by the Michigan State Police.

Det. Sgt. Patrick McPherson tells 6 News after learning about the “financial irregularities” in DeWitt, Sheriff officials began reviewing the books of the department’s mounted division. The mounted division is a volunteer unit run by a nonprofit organization. Grysen served as treasurer for the nonprofit.

“We did our own due diligence,” he says. The due diligence led to a formal investigation which, McPherson says “is expected to become a criminal matter in the future.”

Grysen was escorted from DeWitt City Hall on Aug. 16 after officials there discovered “financial irregularities.” She was fired by Mayor Sue Leeming two days later. Monday, the DeWitt City Council unanimously supported Leeming’s decision.

6 News left a voicemail for Grysen this afternoon. She has not responded to previous attempts to speak with her, including visits to her home by reporters.