Section 10.7 Bias or Interest

• Library: Civil Trial Practice 2015 Supp

4. (§10.7) Bias or Interest

The interest or bias of a witness and the witness’s relation to or feelings toward the parties are never irrelevant matters and may properly be inquired into on cross-examination. Houfburg v. Kansas City Stock Yards Co. of Me., 283 S.W.2d 539, 548 (Mo. 1955); Anderson v. Wittmeyer, 895 S.W.2d 595, 600 (Mo. App. W.D. 1995); Vosevich v. Doro,Ltd., 536 S.W.2d 752, 760 (Mo. App. E.D. 1976). Circumstances showing interest or bias do not need to have an evidentiary bearing on the issues involved in the case. Thornton v. Vonallmon, 456 S.W.2d 795, 798 (Mo. App. S.D. 1970); § 491.010, RSMo 2000.

When bias of a witness is the subject of cross-examination, the trial court has its broadest discretion as to the extent of the examination. Cignetti v. Camel, 692 S.W.2d 329, 338 (Mo. App. E.D. 1985). The extent to which counsel may go in demonstrating bias or interest, however, is not unlimited. Brug v. Mfrs. Bank & Trust Co., 461 S.W.2d 269, 275–76 (Mo. banc 1970); St. Francis Med. Ctr. v. Sheffer, 892 S.W.2d 394, 397 (Mo. App. E.D. 1995).

A party should be afforded the opportunity to display before the jury bias, hostility, or prejudices held by the adverse witness so that the jury can determine with greater accuracy the appropriate weight to be given to that witness’s testimony. State v. Hedrick, 797 S.W.2d 823 (Mo. App. W.D. 1990). The facts and circumstances showing bias may be shown specifically by either cross-examination of the witness to be impeached or by the introduction of extrinsic evidence. Id...