Article VI. Witnesses
Rule 616: Impeachment by bias or prejudice.
A party may offer evidence by cross-examination, extrinsic evidence, or both, that a witness is biased in favor of or prejudiced against a party or another witness.
Advisory Commission Comments.
Bias is an important ground for impeachment. See Creeping Bear v. State, 113 Tenn. 322, 87 S.W. 653 (1905).