Mich. R. Evid. 606

As amended through April 3, 2024
Rule 606 - Juror's Competency as a Witness
(a) At the Trial. A juror may not testify as a witness before the other jurors at the trial. A party need not object to preserve the issue.
(b) During an Inquiry into the Validity of a Verdict or Indictment.
(1) Prohibited Testimony or Other Evidence. During an inquiry into the validity of a verdict or indictment, a juror may not testify about any statement made or incident that occurred during the jury's deliberations; the effect of anything on that Juror's or another juror's vote; or any juror's mental processes concerning the verdict or indictment. The court may not receive a juror's affidavit or evidence of a juror's statement on these matters.
(2) Exceptions. A juror may testify about whether:
(A) extraneous prejudicial information was improperly brought to the jury's attention;
(B) an outside influence was improperly brought to bear on any juror; or
(C) a mistake was made in entering the verdict on the verdict form.

Mich. R. Evid. 606

Amended September 20, 2023, effective 1/1/2024.