COMPETENCY OF JUROR AS WITNESS
(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. If the juror is called so to testify, the opposing party shall be afforded an opportunity to object outside the presence of the jury.
(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 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, except that a juror may testify on the question whether extraneous prejudicial information was improperly brought to the jury's attention or whether any outside influence was improperly brought to bear upon any juror. Nor may a juror's affidavit or evidence of any statement by the juror concerning a matter about which the juror would be precluded from testifying be received for these purposes.
The language of this rule is identical to the federal rule. Subsection (a) of this rule changes the law in South Carolina in two regards. First, while prior law allowed a juror to testify as to venue, State v. Vari, 35 S.C. 175, 14 S.E. 392 (1892) (juror allowed to testify as to isolated, particular matter such as value or venue but not as to general facts and circumstances of the offense), this subsection would prohibit such testimony. Second, the prior law did not require that the party opposing the calling of a juror as a witness be given an opportunity to object outside the presence of the jury.
Subsection (b) is consistent with the general rule that a juror may not present testimony as to the deliberations in the jury room; as to any mistake, irregularity, or misconduct on the part of the jurors; or which would impeach the verdict or contradict the record. Barsh v. Chrysler Corp., 262 S.C. 129, 203 S.E.2d 107 (1974); State v. Wells, 249 S.C. 249, 153 S.E.2d 904 (1967); Caines v. Marion Coca-Cola Bottling Co., 196 S.C. 502, 14 S.E.2d 10 (1941). An affidavit of a juror has been admitted on a post-trial motion "with great hesitation" when there was an allegation that a party had attempted to influence the juror. Cohen v. Robert, 33 S.C.L. (2 Strob.) 410 (1848). The rule is also consistent with South Carolina cases holding that no one may invade the secrecy of a grand jury's deliberations. State v. Sanders, 251 S.C. 431, 163 S.E.2d 220 (1968); Margolis v. Telech, 239 S.C. 232, 122 S.E.2d 417 (1961).