Colo. R. Evid. 606 (2026)

(a) At the trial. A member of the jury may not testify as a witness before that jury in the trial of the case in which the juror is sitting. No objection need be made in order to preserve the point.

(b) Inquiry Into Validity of Verdict or Indictment. Upon an inquiry into the validity of a verdict or indictment, a juror may not testify as to any matter or statement occurring during the course of the jury's deliberations or to the effect of anything upon that juror’s or any other juror's mind or emotions as influencing the juror to assent to or dissent from the verdict or indictment or concerning the juror’s mental processes in connection therewith. But a juror may testify about (1) whether extraneous prejudicial information was improperly brought to the jurors' attention, (2) whether any outside influence was improperly brought to bear upon any juror, or (3) whether there was a mistake in entering the verdict onto the verdict form. A juror's affidavit or evidence of any statement by the juror may not be received on a matter about which the juror would be precluded from testifying.

Source: Entire rule amended and effective and committee comment added and effective September 27, 2007.

Amended by Rule Change 2025(05), adopted January 16, 2025, effective immediately.