Witness Truthfulness: Cross vs. Extrinsic Proof

Revised stem

A church hired a licensed contractor to build a new fellowship hall. After the work was completed, the church sued the contractor for breach of contract, claiming that the building had serious structural defects. The church called a structural engineer as an expert witness to testify about the cost of repairs. On cross-examination, the contractor's attorney asks the engineer whether he had previously provided false testimony as a witness in his own divorce proceedings. This question is:

Answer flow

01 Identify the form of the impeachment: the lawyer asks the expert a question on cross-examination.

02 Identify the act: allegedly false testimony in the expert's own divorce proceeding.

03 Connect the act to truthfulness because false testimony is a dishonest act.

04 Apply FRE 608(b): the court may allow cross-examination about a specific act probative of truthfulness.

05 Keep the extrinsic-evidence bar in its lane: it blocks outside proof, not the question itself.

06 Cut A because it applies the extrinsic-evidence limit to the wrong procedural form.

07 Cut C because it turns a limited rule into an absolute ban.

08 Cut D because authentication does not make barred extrinsic proof admissible.

09 Choose B.

A / trap

right_rule_wrong_form / extrinsic-evidence overread

Inadmissible, because impeachment on a collateral matter may not be proved by extrinsic evidence.

A states the extrinsic-evidence limit, but the lawyer is asking the expert a question on cross-examination. FRE 608(b) bars outside proof of the act; it does not automatically bar the question.

B / correct

residue / FRE 608(b) cross-examination lane

Admissible, because the questioning occurred on cross-examination of the expert witness.

The prior false testimony is a specific dishonest act that bears on the expert's truthfulness. The inquiry is on cross-examination, so it may be allowed in the court's discretion.

C / trap

tiered_absolute / overbroad character rule

Inadmissible, because a witness's character for truthfulness cannot be attacked by specific instances of conduct.

C overstates the rule. Specific acts generally cannot be proved with extrinsic evidence, but truthful-character impeachment may include cross-examination about dishonest acts that bear on truthfulness.

D / trap

authentication_not_admissibility / wrong proof route

Admissible, because a certified transcript of the prior testimony would be self-authenticating.

Authentication does not solve the FRE 608(b) problem. A transcript may prove what happened, but extrinsic proof of the prior act is barred when offered only to attack truthfulness.

C3 locks

Red axis: Question vs. proof: asking about a dishonest act on cross is different from proving that act with a transcript or another outside source.

Purple profile: The answer set offers one proper cross-examination route, then distracts with collateral-proof, overbroad character, and authentication reasons.

Blue signal: The phrase on cross-examination is the signal that keeps the issue inside the FRE 608(b) inquiry lane.

Orange repair: Student habit to repair: seeing a specific act and stopping at barred, without asking whether the lawyer is only asking about the act on cross.

Reusable keys

Gold Key / GK-EVIDENCE-TRUTHFULNESS-01
A witness may be asked on cross-examination about a specific dishonest act if the act is probative of that witness's truthfulness; the examiner may not prove the act with extrinsic evidence just for that attack.

Silver Key / SK-EVIDENCE-CROSS-EXTRINSIC-01
First classify the impeachment method. Cross-examination may be allowed; a transcript or other outside proof is the separate barred route.

Trap Key / TK-EVIDENCE-AUTHENTICATION-NOT-ADMISSIBILITY
A document can be authenticated and still excluded if it is offered as extrinsic proof of a specific truthfulness act.

LeadMe steps

01 Ask whether the lawyer is asking a question or offering proof.

02 Identify whose credibility is being attacked.

03 Classify false testimony as a dishonest act probative of truthfulness.

04 Apply the cross-examination side of FRE 608(b).

05 Hold the extrinsic-evidence bar for transcripts, documents, or other outside proof.

06 Reject the absolute specific-act answer.

07 Reject authentication as a substitute for admissibility.

08 Pick the cross-examination answer.

Drill seeds