In Cross-Examination Handbook: Persuasion, Strategies, and Techniques, we explore both the evidentiary and ethical issues that proof of a prior inconsistent statement raise. If a lawyer wishes to impeach with a prior inconsistent statement, can the lawyer offer the prior statement into evidence through extrinsic evidence, such as testimony by the witness to whom the prior statement was given? Federal Rule or Evidence 613(b) clearly states: “Extrinsic evidence of a witness’s prior inconsistent statement is admissible only if the witness is given an opportunity to explain or deny the statement and an adverse party is given an opportunity to examine the witness about it, or if justice so requires. This subdivision (b) does not apply to an opposing party’s statement under Rule 801(d)(2).” Rule 801(d)(2) defines a statement offered against an opposing party as not hearsay.
If the witness admits to having made the prior statement, the trial court has the discretion to exclude the prior statement as cumulative under Rule 403. On the other hand, if the witness denies having made the statement, the extrinsic evidence is admissible unless the statement is on a collateral matter. If it is on a collateral matter, the cross-examiner is stuck with the witness’s answer.
A lawyer should never attempt to impeach a witness with a prior inconsistent statement if the prior statement cannot be proven. Some lawyers ask about a prior statement without proof of this in the hopes that either the witness will admit it or, if the witness denies it, that the jury will believe the statement was made anyway. Whatever the examiner’s motivation, it is unprofessional conduct. Model Rule of Professional Conduct 3.4(e) states “a lawyer shall not in trial, allude to any matter that the lawyer does not reasonably believe is relevant or that will not be supported by admissible evidence, assert personal knowledge of facts in issue except when testifying as a witness. . .”
The biggest error comes when counsel has had a one-on-one interview with the witness, and the witness said something only counsel’s ears have heard. When the witness denies making the prior inconsistent statement, counsel cannot ethically blurt out “But didn’t you tell me . . .?” A cross-examiner cannot become a witness without running afoul of ethical requirements under MRPC 3.7 prohibiting a lawyer from being a witness except under limited circumstances. This rookie mistake can be avoided by always having a prover (person whom the lawyer could call to testify) present or another means of proving the witness’s statements when interviewing a person who is or might become an adverse witness.