Intro to the Fereal Rules of Evidence - 43

5. W’s Bias/ interest
Although there is no rule on bias in the Federal Rules, in the United States v. Abel, 469 U.S. 45, 51 (1984), the Supreme Court held that impeachment of a witness for bias was proper.

a. Rationale
Evidence that a witness is biased or has an interest in the outcome of a suit tends to show that the witness has a motive to lie.

b. Examples of bias
i) a friendly feeling: a personal relationship,
ii) hostility to a party
iii) self-interest in the outcome.
iv) a member of an organization

c. Foundation
i) Cross examination
The examiner may cross-examine the witness to show bias without laying any foundation.
ii) Extrinsic evidence
The FRE do not explicitly require a foundation – that is, only after the witness is asked about an alleged bias and denies it - before extrinsic evidence of bias may be introduced. Under FRE 611(a), however, a court my require at its discretion that a foundation be laid before the extrinsic evidence is introduced.