Mich. Comp. Laws § 725.252
Juror in justice or police court or coroner's inquest in Wayne county; former service as disqualification or cause of challenge.
No person shall be qualified to sit as a juror in any justice or police court of Wayne county, or on an inquest before any coroner, who has already sat as a juror in said justice or police court, or on an inquest before said coroner, more than 3 times during the calendar year next preceding the time when he is summoned…