Michigan Compiled Laws, Chapter 780. Criminal Procedure § 780.316

Sec. 6. (1) Except as provided in subsections (2) and (3), a law enforcement agency shall retain an evidentiary audio and video recording recorded by a body-worn camera for not less than 30 days from the date the recording is made.

(2) A law enforcement agency shall retain audio and video recordings that are the subject of an ongoing criminal or internal investigation, or an ongoing criminal prosecution or civil action, until the completion of the ongoing investigation or legal proceeding.

(3) A law enforcement agency shall retain audio and video recorded by a body-worn camera for not less than 3 years after the date the recording is made if the recording is relevant to a formal complaint against a law enforcement officer or agency.

(4) If a complaint against a law enforcement officer or law enforcement agency is made after the expiration of the retention period described in subsection (1), (2), or (3) or a law enforcement agency is unable to produce an audio and video recording related to the complaint in any criminal prosecution or civil action as a result of a technical failure or human error, this act does not create a presumption that the audio and video recording would corroborate either the prosecution's or the defendant's version of events in a criminal prosecution or the plaintiff's or the defendant's version in a civil action.