Mich. Comp. Laws § 750.139

Sec. 139. (1) Except as provided in subsection (2), a child under 18 years of age while under arrest, confinement, or conviction for a crime must not be placed in an apartment or cell of a prison or place of confinement with 1 or more adults who are under arrest, confinement, or conviction for a crime, be permitted to remain in any court room during the trial of adults, or be transported in a vehicle used to transport inmates with adults charged with or convicted of a crime. (2) Subsection (1) does not apply to prisoners being transported to or from, or confined in a youth correctional facility operated by the department of corrections or a private vendor under section 20g of the corrections code of 1953, 1953 PA 232, MCL 791.220g. (3) All cases involving the commitment or trial of children under 18 years of age for any crime or misdemeanor, before any court, must be heard and determined by the court at a suitable time, designated by the court, separate and apart from the trial of other criminal cases. (4) A person who violates this section is guilty of a misdemeanor.