Michigan Compiled Laws, Chapters 760 to 777 Code of Criminal Procedure § 767.40a

Sec. 40a.(1) The prosecuting attorney shall attach to the filed information a list of all witnesses known to the prosecuting attorney who might be called at trial and all res gestae witnesses known to the prosecuting attorney or investigating law enforcement officers.

(2) The prosecuting attorney shall be under a continuing duty to disclose the names of any further res gestae witnesses as they become known.

(3) Not less than 30 days before the trial, the prosecuting attorney shall send to the defendant or his or her attorney a list of the witnesses the prosecuting attorney intends to produce at trial.

(4) The prosecuting attorney may add or delete from the list of witnesses he or she intends to call at trial at any time upon leave of the court and for good cause shown or by stipulation of the parties.

(5) The prosecuting attorney or investigative law enforcement agency shall provide to the defendant, or defense counsel, upon request, reasonable assistance, including investigative assistance, as may be necessary to locate and serve process upon a witness. The request for assistance shall be made in writing by defendant or defense counsel not less than 10 days before the trial of the case or at such other time as the court directs. If the prosecuting attorney objects to a request by the defendant on the grounds that it is unreasonable, the prosecuting attorney shall file a pretrial motion before the court to hold a hearing to determine the reasonableness of the request.

(6) Any party may within the discretion of the court impeach or cross-examine any witnesses as though the witness had been called by another party.