## Facts

- Seminole Electric Cooperative, Inc. obtained a large loan to build a power plant and access road; the loan was federally guaranteed, and a federal agency retained supervisory and approval authority over aspects of the project.
- William M. Conover, Seminole’s procurement manager, and Anthony R. Tanner were friends with prior business dealings.
- Road-construction and fill-material contracts were awarded to Tanner’s company under favorable bidding specifications prepared within Conover’s procurement department.
- Tanner paid Conover more than $30,000, characterized as payments related to personal transactions.
- Conover repeatedly intervened in disputes between Seminole and Tanner on terms favorable to Tanner.
- After a federal agency complained about Tanner’s bond, Conover communicated with a new bonding company in a manner that misrepresented the road’s completion status.
- Tanner and Conover were indicted and convicted in federal district court of conspiracy to defraud the United States (18 U.S.C. § 371) and mail fraud (18 U.S.C. § 1341).
- After the verdict, petitioners sought leave to interview jurors and moved for a new trial, alleging jurors drank alcohol during lunch and slept during trial.
- The district court ruled juror testimony about jurors’ own intoxication was inadmissible under Federal Rule of Evidence 606(b), permitted nonjuror evidence, and denied relief.
- Petitioners later submitted a juror affidavit alleging substantial alcohol and drug use by jurors during trial; the district court again refused to consider juror statements under Rule 606(b) and denied relief.
- The court of appeals affirmed; the Supreme Court granted review on the juror-misconduct question and the scope of § 371.

## Issues

1. Whether Federal Rule of Evidence 606(b) permits juror testimony or affidavits about jurors’ alcohol and drug use during trial to impeach the verdict, and whether the district court was required to hold an additional evidentiary hearing.
2. Whether conduct involving a private cooperative with a federally guaranteed loan constitutes a conspiracy to defraud the United States under 18 U.S.C. § 371 when the alleged scheme primarily defrauded the cooperative.

## Decision

- The Court held that Rule 606(b) barred juror testimony and affidavits describing jurors’ alcohol and drug use during trial because such behavior is internal juror misconduct, not “outside influence.”
- The Court held the district court did not err in refusing to conduct an additional evidentiary hearing based on juror statements and in denying a new trial where nonjuror evidence was insubstantial.
- On § 371, the Court rejected the view that defrauding a federally connected private entity automatically equals defrauding the United States.
- The Court held that a conspiracy to cause the cooperative to make misrepresentations to a federal agency could fall within § 371.
- The Court remanded for further consideration of whether the evidence established a conspiracy aimed at deceiving the federal agency.

## Legal Principles

- Federal Rule of Evidence 606(b) generally prohibits juror testimony to impeach a verdict concerning internal jury matters, including juror inattentiveness, drowsiness, or intoxication.
- The Rule’s exceptions for “extraneous prejudicial information” and “outside influence” apply to external inputs or pressures on jurors, not to jurors’ voluntary substance use.
- A defendant’s interest in a competent jury is primarily protected through pre-verdict tools (e.g., voir dire, courtroom observation, and contemporaneous reporting) and through admissible nonjuror evidence of misconduct.
- Under 18 U.S.C. § 371, a conspiracy “to defraud the United States” requires deceit directed at impairing or obstructing a federal governmental function; downstream federal financial exposure from fraud on a private party is not alone sufficient.

## Conclusion

The Court enforced Rule 606(b)’s no-impeachment bar to exclude juror testimony about jurors’ own substance use and upheld the denial of further post-verdict inquiry, while limiting § 371 by requiring that the deceit target a federal agency’s functions rather than merely a federally connected private entity.


Tanner v. United States, 483 U.S. 107 (1987)