Hon. Mona S. Armstrong is a judge for the Seventy-Second District Court of Michigan in St. Clair County. She was appointed to the bench by former Governor Gretchen Whitmer in March 2020, filling the vacancy created by the retirement of the Hon. Cynthia S. Platzer (Ret.).
Prior to her appointment, Armstrong was a senior assistant prosecuting attorney with the St. Clair County Prosecuting Attorney’s Office. She first joined the office as an assistant prosecuting attorney, having held that position for almost twenty-five years, and she handled a caseload that included primarily homicides and other high-profile cases.
Armstrong also taught as an adjunct faculty member in the Criminal Justice Department at St. Clair County Community College and was a research attorney for the Thirty-First Circuit Court.
She received a B.A. in political science and pre-law from Michigan State University in 1991. Armstrong went on to complete a J.D. at Wayne State University Law School in 1994.
She is a member of the Prosecuting Attorneys Association of Michigan and has been involved with the St. Clair County Community Foundation and the McLaren Port Huron Hospital Board of Trustees (chair).
Armstrong and her husband, Todd, have two children. The family resides in Fort Gratiot Township.