Chapter 8 - § 8.2 • BIAS, MOTIVE, PREJUDICE, AND INTEREST

• Jurisdiction: Colorado

§ 8.2 • BIAS, MOTIVE, PREJUDICE, AND INTEREST

§ 8.2.1—Introduction

Impeachment on bias, motive, prejudice, and interest is constitutionally grounded. Delaware v. Fensterer, 474 U.S. 15 (1985); Merritt v. People, 842 P.2d 162, 166 (Colo. 1992) ("Such confrontation is not satisfied simply by having the witnesses physically present in court, but requires that the defendant be given an opportunity for effective cross-examination"). Attorneys are permitted a "thorough inquiry into the motives of witnesses." People v. Taylor, 545 P.2d 703, 705 (Colo. 1976); People v. Simmons, 512 P.2d 193, 195 (Colo. 1973) ("defendant should be allowed wide latitude to cross-examine a prosecution witness for the purpose of showing bias or undue interest."). Bias, motive, prejudice, and interest are relevant to the trier of fact. Davis v. Alaska, 415 U.S. 308 (1974).

Relevance is a necessary but not necessarily sufficient factor, and relevant evidence can be excluded "if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence." Merritt, 842 P.2d at 166. Trial courts have "some discretion in limiting [impeachment by] cross-examination where it is without probative force." Simmons, 512 P.2d at 195.

When impeaching a witness for bias, motive, prejudice, or interest, attorneys should craft clear lines of questioning to avoid confusion and as signal to the court, as the "opportunity for effective cross-examination does not mean that cross-examination must actually be effective." Merritt, 842 P.2d at 166 (citing Fensterer, 474 U.S. 15).

A witness's motive for testifying or interest in the outcome of the case is potent impeachment material. Any motive or interest can color a witness's testimony and should be highlighted with an effective examination. Bias, motive, prejudice, and interest can come in many different forms and often fit nicely with themes and theories of a case because they can help a jury understand a witness's point of view.

Impeachment for bias, motive, prejudice, or interest can be far-reaching and even muddy otherwise clear constitutional waters. For example, while the First Amendment to the U.S. Constitution protects the freedom of association, "evidence of gang membership may be admissible to show bias, as res gestae evidence, to show motive and the particular circumstances of the crime."...