Impeachment of Witnesses

Credibility may be attacked by: (1) prior inconsistent statements; (2) bias, interest, or motive to lie; (3) defects in perception or memory (sensory or mental capacity); (4) contradiction (proving the witness wrong on a substantive fact); (5) reputation or opinion evidence of an untruthful character under FRE 608(a); (6) specific acts of untruthfulness under FRE 608(b); and (7) prior convictions under FRE 609.

FRE 608(a) lets a character witness testify to the target witness's reputation or give an opinion that the target is untruthful; evidence of TRUTHFUL character is admissible only AFTER the witness's character for truthfulness has been attacked.

FRE 608(b) is the heavily tested limit: on cross-examination, the court MAY allow inquiry into specific instances of the witness's conduct that are probative of truthfulness (e.g., lying on a job application, prior fraud), but EXTRINSIC evidence is NOT admissible to prove those instances — the cross-examiner must accept the witness's answer and may not call other witnesses or introduce documents to prove the act.

FRE 609 distinguishes two categories. First, any crime — felony or misdemeanor — whose elements REQUIRED proving a dishonest act or false statement (crimen falsi: perjury, fraud, embezzlement, false pretenses) MUST be admitted; the court has NO discretion to exclude it under 403, subject only to the 10-year limit.

Second, other crimes punishable by death or imprisonment over one year (felonies) are admissible subject to balancing: for an ordinary witness, the standard FRE 403 test applies; but when the witness is the CRIMINAL DEFENDANT, a special REVERSE-403 test applies — the conviction is admitted only if its probative value OUTWEIGHS its prejudicial effect to the defendant. Convictions (or release from confinement) more than 10 years old are presumptively inadmissible and come in only if probative value substantially outweighs prejudice and the proponent gives notice. Pardons based on innocence and most juvenile adjudications are excluded.

A pending appeal does not bar use.

A prior inconsistent statement (PIS) impeaches by showing the witness has told a different story. Under FRE 613(a) you need not show the witness the statement before asking about it, but on request you must show it to opposing counsel. Under FRE 613(b), EXTRINSIC evidence of a PIS is admissible only if the witness is given an opportunity to explain or deny it and the opposing party may examine the witness — the timing is flexible (you can call the impeaching witness later).

Two limits: the PIS must concern a NON-collateral matter, and using it substantively (for its truth) requires that it was given under oath at a trial, hearing, or deposition (FRE 801(d)(1)(A)); otherwise it impeaches credibility only. Bias is never collateral, so extrinsic evidence of bias (a fee arrangement, a grudge, an interest in the outcome) is always admissible after a foundation; the Supreme Court confirmed bias impeachment in United States v. Abel.

Several cross-cutting principles govern every impeachment method. The COLLATERAL-MATTER doctrine determines when extrinsic evidence is permitted: a matter is non-collateral (and thus provable by extrinsic evidence) if it bears on the merits of the case or on a recognized non-collateral impeachment ground — bias, sensory or mental defect, conviction, or untruthful character via reputation/opinion.

A matter relevant ONLY to contradict the witness on a tangential point is collateral, and the cross-examiner is bound by the witness's answer; FRE 608(b)'s 'no extrinsic evidence of specific untruthful acts' is the classic application, leaving the examiner 'stuck with the answer.' BIAS, by contrast, is NEVER collateral — extrinsic proof of a fee arrangement, a family relationship, a plea deal, a grudge, or a financial stake is always admissible after a foundation, and United States v. Abel confirmed that the FRE preserve bias impeachment even though no rule expressly names it.

After a witness is impeached, REHABILITATION is permitted but must meet the attack: FRE 608(a) allows evidence of TRUTHFUL character only after the witness's character for truthfulness has been attacked (by opinion/reputation, a 609 conviction, or a sharp suggestion of fabrication — but not by a mere contradiction or a single prior inconsistent statement), and FRE 801(d)(1)(B) admits a prior CONSISTENT statement to rebut an express or implied charge of recent fabrication or improper motive, provided under Tome v. United States that the consistent statement predates the alleged motive to fabricate.

FRE 610 separately bars evidence of a witness's religious beliefs or opinions to attack or support credibility, though such evidence may show bias (membership in a church that is a party, for instance).

The 609 framework rewards precision: crimen falsi convictions (perjury, fraud, false statement, embezzlement, criminal-fraud offenses) are admitted with NO 403 discretion subject only to the ten-year clock; other felonies face standard 403 balancing for ordinary witnesses but the protective REVERSE-403 test when the witness is the accused (admitted only if probative value outweighs prejudice TO THE DEFENDANT); and convictions more than ten years old (measured from conviction or release) are presumptively excluded absent specific notice and a finding that probative value substantially outweighs prejudice.

California's contrasts are sharp: under People v. Castro and Proposition 8, any felony of moral turpitude impeaches a criminal witness subject to CEC 352, People v. Wheeler extends this to misdemeanor moral-turpitude CONDUCT (provable even by extrinsic evidence, unlike FRE 608(b)), and CEC 780 lists the permissible credibility factors while CEC 786-790 cap certain attacks; CEC 1235's substantive use of all prior inconsistent statements completes a regime markedly broader than the federal rules.

Impeachment Methods: Extrinsic Evidence Allowed?

Proposition 8 transformed California impeachment in criminal cases. People v. Castro and CEC 788 + Prop 8 permit impeaching a witness with any prior FELONY involving MORAL TURPITUDE (a readiness to do evil), and People v. Wheeler allows misdemeanor CONDUCT involving moral turpitude as well — all subject to CEC 352 balancing. This sweeps in crimes (like robbery or assault) that are NOT crimen falsi and would face strict balancing under FRE 609. Moral-turpitude conduct may even be proved by extrinsic evidence in a criminal case (a key contrast with FRE 608(b)'s no-extrinsic rule), again subject to 352.

Second major distinction: CEC 1235 makes ALL prior inconsistent statements admissible as SUBSTANTIVE evidence (for their truth), not merely to impeach, and they need NOT have been made under oath — far broader than FRE 801(d)(1)(A). On a CA criminal essay, lead with moral turpitude + 352 and remember PIS come in for the truth.