19-19-606. 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. If a juror is called to testify, the court must give a party an opportunity to object outside the jury's presence.
(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.
Source: SL 1979, ch 358 (Supreme Court Rule 78-2, Rule 606); SDCL §§19-14-6, 19-14-7; SL 2016, ch 239 (Supreme Court Rule 15-39), eff. Jan. 1, 2016.