Q1: What area of law does Tanner v. United States primarily address?
Evidence
Q2: What was the central legal issue in Tanner v. United States?
Does Federal Rule of Evidence 606(b) permit jurors to testify post-verdict that they were intoxicated during trial and deliberations in order to impeach the verdict, and does the Sixth Amendment require an exception to Rule 606(b) for such evidence?
Q3: What rule did the court apply?
Under Federal Rule of Evidence 606(b), during an inquiry into the validity of a verdict, a juror may not testify about (1) any statement made or incident that occurred during the jury's deliberations; (2) the effect of anything on a juror's mind or emotions as influencing the juror to assent to or dissent from the verdict; or (3) the juror's mental processes concerning the verdict. Juror affidavits on these matters are likewise inadmissible. The rule recognizes narrow exceptions that allow juror testimony about whether (a) extraneous prejudicial information was improperly brought to the jury's attention or (b) an outside influence was improperly brought to bear on any juror. (Modern formulations also allow proof of a clerical mistake in entering the verdict.)
Q4: What was the court's holding?
FRE 606(b) bars juror testimony regarding jurors' alcohol and drug use and related inattentiveness because such matters are internal to the jury, not an outside influence. The Sixth Amendment does not require an exception to Rule 606(b) for evidence of juror intoxication. The district court properly excluded juror testimony and, based on the non-juror evidence presented, did not err in declining to order a new trial.
Q5: Why is Tanner v. United States significant?
Tanner establishes the modern internal/external distinction under Rule 606(b) and powerfully reinforces the no-impeachment rule. It teaches that post-verdict challenges based on juror intoxication, inattentiveness, or similar internal misconduct cannot rely on juror affidavits or testimony. Instead, parties must marshal non-juror evidence and, ideally, raise the issue during trial when the court can intervene. Tanner has been repeatedly cited to bar juror testimony about internal matters (e.g., Warger v. Shauers) and remains the default rule in federal courts. Its constitutional holding has one notable limit: Peña‑Rodriguez v. Colorado later recognized a narrow Sixth Amendment exception requiring inquiry into clear statements of racial animus during deliberations. Outside that narrow context, Tanner controls.