Federal Rules of Evidence – Rule 606 (through March 1, 2020)
Jurors cannot testify before other jurors at trial.
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.
Selected Committee Notes
Subdivision (a). The considerations which bear upon the permissibility of testimony by a juror in the trial in which he is sitting as juror bear an obvious similarity to those evoked when the judge is called as a witness. See Advisory Committee’s Note to Rule 605. The judge is not, however in this instance so involved as to call for departure from usual principles requiring objection to be made; hence the only provision on objection is that opportunity be afforded for its making out of the presence of the jury. Compare Rules 605.
Subdivision (b). Whether testimony, affidavits, or statements of jurors should be received for the purpose of invalidating or supporting a verdict or indictment, and if so, under what circumstances, has given rise to substantial differences of opinion. The familiar rubric that a juror may not impeach his own verdict, dating from Lord Mansfield’s time, is a gross oversimplification. The values sought to be promoted by excluding the evidence include freedom of deliberation, stability and finality of verdicts, and protection of jurors against annoyance and embarrassment. McDonald v. Pless, 238 U.S. 264, 35 S.Ct. 785, 59 L.Ed. 1300 (1915). On the other hand, simply putting verdicts beyond effective reach can only promote irregularity and injustice. The rule offers an accommodation between these competing considerations.
The mental operations and emotional reactions of jurors in arriving at a given result would, if allowed as a subject of inquiry, place every verdict at the mercy of jurors and invite tampering and harassment. See Grenz v. Werre, 129 N.W.2d 681 (N.D. 1964). The authorities are in virtually complete accord in excluding the evidence. Fryer, Note on Disqualification of Witnesses, Selected Writings on Evidence and Trial 345, 347 (Fryer ed. 1957); Maguire, Weinstein, et al., Cases on Evidence 887 (5th ed. 1965); 8 Wigmore §2340 (McNaughton Rev. 1961). As to matters other than mental operations and emotional reactions of jurors, substantial authority refuses to allow a juror to disclose irregularities which occur in the jury room, but allows his testimony as to irregularities occurring outside and allows outsiders to testify as to occurrences both inside and out. 8 Wigmore §2354 (McNaughton Rev. 1961). However, the door of the jury room is not necessarily a satisfactory dividing point, and the Supreme Court has refused to accept it for every situation. Mattox v. United States, 146 U.S. 140, 13 S.Ct. 50, 36 L.Ed. 917 (1892).
Under the federal decisions the central focus has been upon insulation of the manner in which the jury reached its verdict, and this protection extends to each of the components of deliberation, including arguments, statements, discussions, mental and emotional reactions, votes, and any other feature of the process. Thus testimony or affidavits of jurors have been held incompetent to show a compromise verdict, Hyde v. United States, 225 U.S. 347, 382 (1912); a quotient verdict, McDonald v. Pless, 238 U.S. 264 (1915); speculation as to insurance coverage, Holden v. Porter, 495 F.2d 878 (10th Cir.1969), Farmers Coop. Elev. Ass’n v. Strand, 382 F.2d 224, 230 (8th Cir. 1967), cert. denied 389 U.S. 1014; misinterpretations of instructions, Farmers Coop. Elev. Ass’n v. Strand, supra; mistake in returning verdict, United States v. Chereton, 309 F.2d 197 (6th Cir. 1962); interpretation of guilty plea by one defendant as implicating others, United States v. Crosby, 294 F.2d 928, 949 (2d Cir. 1961). The policy does not, however, foreclose testimony by jurors as to prejudicial extraneous information or influences injected into or brought to bear upon the deliberative process. Thus a juror is recognized as competent to testify to statements by the bailiff or the introduction of a prejudicial newspaper account into the jury room, Mattox v. United States, 146 U.S. 140 (1892). See also Parker v. Gladden, 385 U.S. 363 (1966).
This rule does not purport to specify the substantive grounds for setting aside verdicts for irregularity; it deals only with the competency of jurors to testify concerning those grounds. Allowing them to testify as to matters other than their own inner reactions involves no particular hazard to the values sought to be protected. The rules is based upon this conclusion. It makes no attempt to specify the substantive grounds for setting aside verdicts for irregularity.
See also Rule 6(e) of the Federal Rules of Criminal Procedure and 18 U.S.C. §3500, governing the secrecy of grand jury proceedings. The present rules does not relate to secrecy and disclosure but to the competency of certain witnesses and evidence.