Conn. R. Evid. 6-5
The credibility of a witness may be impeached by evidence showing bias for, prejudice against, or interest in any person or matter that might cause the witness to testify falsely.
Conn. Code. Evid. 6-5
COMMENTARY
Section 6-5 reflects established law. E.g., State v. Alvarez, 216 Conn. 301, 318-19, 579 A.2d 515 (1990); Fordiani's Petition for Naturalization, 99 Conn. 551, 560-62, 121 A. 796 (1923); see General Statutes § 52-145(b) (''[a] person's interest in the outcome of [an] action . . . may be shown for the purpose of affecting his [or her] credibility''); see also State v. Bova, 240 Conn. 210, 224-26, 690 A.2d 1370 (1997); State v. Barnes, 232 Conn. 740, 745-47, 657 A.2d 611 (1995).
While a party's inquiry into facts tending to establish a witness' bias, prejudice or interest is generally a matter of right, the scope of examination and extent of proof on these matters are subject to judicial discretion. E.g., State v. Mahmood, 158 Conn. 536, 540, 265 A.2d 83 (1969); see also Section 4-3.
The range of matters potentially giving rise to bias, prejudice or interest is virtually endless. See State v. Cruz, 212 Conn. 351, 360, 562 A.2d 1071 (1989). A witness may be biased by having a friendly feeling toward a person or by favoring a certain position based upon a familial or employment relationship. E.g., State v. Santiago, 224 Conn. 325, 332, 618 A.2d 32 (1992); State v. Asherman, 193 Conn. 695, 719-20, 478 A.2d 227 (1984), cert. denied, 470 U.S. 1050, 105 S. Ct. 1749, 84 L. Ed. 2d 814 (1985). A witness may be prejudiced against a person or position based upon a prior quarrel with the person against whom the witness testifies; see Beardsley v. Wildman, 41 Conn. 515, 517 (1874); or by virtue of the witness' animus toward a class of persons. Jacek v. Bacote, 135 Conn. 702, 706, 68 A.2d 144 (1949). A witness may have an interest in the outcome of the case independent of any bias or prejudice when, for example, he or she has a financial stake in its outcome; see State v. Colton, 227 Conn. 231, 250-51, 630 A.2d 577 (1993); or when the witness has filed a civil suit arising out of the same events giving rise to the criminal trial at which the witness testifies against the defendant. State v. Arline, 223 Conn. 52, 61, 612 A.2d 755 (1992).
Because evidence tending to show a witness' bias, prejudice or interest is never collateral; e.g., State v. Chance, 236 Conn. 31, 58, 671 A.2d 323 (1996); impeachment of a witness on these matters may be accomplished through the introduction of extrinsic evidence, in addition to examining the witness directly. See, e.g., State v. Bova, supra, 240 Conn. 219; Fairbanks v. State, 143 Conn. 653, 657, 124 A.2d 893 (1956). The scope and extent of proof through the use of extrinsic evidence is subject to the court's discretion, however; State v. Colton, supra, 227 Conn. 249; State v. Shipman, 195 Conn. 160, 163, 486 A.2d 1130 (1985); and whether extrinsic evidence may be admitted to show bias, prejudice or interest without a foundation is also within the court's discretion. E.g., State v. Townsend, 167 Conn. 539, 560, 356 A.2d 125, cert. denied, 423 U.S. 846, 96 S. Ct. 84, 46 L. Ed. 2d 67 (1975); State v. Crowley, 22 Conn. App. 557, 559, 578 A.2d 157, cert. denied, 216 Conn. 816, 580 A.2d 62 (1990).
The offering party must establish the relevancy of impeachment evidence by laying a proper foundation; State v. Barnes, supra, 232 Conn. 747; which may be established in one of three ways: (1) by making an offer of proof; (2) the record independently may establish the relevance of the proffered evidence; or (3) "stating a `good faith belief' that there is an adequate factual basis for [the] inquiry.'' Id.