Presentation of evidence - Specific instances of conduct

Learning Outcomes

This article explains specific instances of conduct as evidence, including:

• Understanding the relationship between specific-act evidence, character evidence, and habit, and why the general propensity ban exists on the MBE.
• Distinguishing when a question involves character proof versus a true non-character purpose, and mapping each fact pattern to the correct Federal Rule (404, 405, 406, 608, 609, 412, 413–415).
• Identifying when specific instances may be used to prove character in criminal and civil cases, including situations where character is an essential element of a claim or defense.
• Applying the rules governing specific acts offered for MIMIC/404(b) purposes, performing Rule 403 balancing, and recognizing when a limiting instruction is required.
• Using specific instances of conduct correctly for impeachment, contrasting 608(b) specific-act impeachment with 609 conviction impeachment and understanding the bar on extrinsic evidence.
• Recognizing when extrinsic evidence of specific acts is barred and when it is permitted, including for 404(b) other-acts evidence, civil defamation, negligent entrustment, and sexual-assault specific-act rules.
• Spotting common MBE traps involving prior crimes, arrests, and misconduct evidence, especially questions that disguise forbidden propensity arguments as permissible non-character purposes.
• Developing a fast, exam-ready issue-spotting sequence for any specific-act fact pattern: purpose, person, proof method, and prejudice.

MBE Syllabus

For the MBE, you are required to understand specific instances of conduct as a form of evidence, with a focus on the following syllabus points:

• The general ban on using specific acts to prove character and action in conformity.
• The limited circumstances in which specific acts may prove character in criminal and civil cases.
• Evidence of other crimes, wrongs, or acts offered for non-character purposes (motive, intent, etc.).
• Impeachment by specific instances of conduct probative of truthfulness, including limits on extrinsic evidence.
• The relationship between specific-act impeachment (FRE 608(b)) and impeachment by conviction (FRE 609).
• How rape-shield rules and sexual-assault specific-act provisions modify the usual character rules.
• The distinction between character, habit, and other-acts evidence, and how Rule 403 balancing applies.

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. In a civil negligence action, the plaintiff offers evidence that the defendant has previously driven drunk three times to prove that he drove drunk on the occasion in question. Under the Federal Rules, this evidence is:
   1. Admissible to prove the defendant’s character for carelessness and action in conformity.
   2. Admissible only if the defendant first offers evidence of his careful driving.
   3. Inadmissible to prove conduct in conformity, but potentially admissible if relevant for a non-character purpose.
   4. Inadmissible because specific instances of conduct are never admissible in civil cases.
2. At a fraud trial, the prosecutor wants to ask a defense witness on cross-examination, “Isn’t it true that you falsified expense reports at your last job?” The witness has never been charged. Which is the best statement of the rule?
   1. The question is barred because it concerns uncharged conduct.
   2. The question is allowed if the judge finds it probative of truthfulness, but the prosecutor must accept the witness’s answer.
   3. The question is allowed, and the prosecutor may introduce the prior employer’s records if the witness denies it.
   4. The question is barred because only convictions may be used to impeach a witness’s character for truthfulness.
3. A defendant is on trial for arson. The prosecution offers evidence that the defendant previously set fire to another building using the same rare accelerant and timing device. The defendant has not opened the door with character evidence. The evidence is:
   1. Inadmissible because it shows propensity to commit arson.
   2. Admissible to prove the defendant’s identity if the similarity is strong enough, subject to Rule 403.
   3. Admissible only if introduced through a character-witness’s cross-examination.
   4. Admissible only if the defendant testifies.
4. In a battery case, a witness denies on cross-examination that she lied on a loan application last year. The cross-examiner wants to call another witness to prove the lie. Under the Federal Rules:
   1. The second witness is admissible because lying on a loan application is highly probative of truthfulness.
   2. The second witness is admissible only if the first witness is a criminal defendant.
   3. The second witness is inadmissible because extrinsic evidence cannot be used solely to prove specific acts of untruthfulness.
   4. The second witness is inadmissible only in civil cases, but admissible in criminal cases.

Introduction

Specific instances of conduct—often called “specific acts”—are heavily tested on the MBE because they sit at the intersection of character evidence, other-acts evidence, and impeachment. The Federal Rules of Evidence sharply limit when you may prove what a person did on other occasions, especially if the real purpose is to depict the person as having a bad character and therefore likely to have acted that way again.

At the same time, the Rules permit specific-act evidence in three major settings:

• To prove something other than character (e.g., motive, intent, identity).
• To prove character when character is itself at issue, or when the criminal defendant opens the door.
• To impeach a witness’s credibility in narrow ways.

On the MBE, the correct answer usually turns on (1) the purpose for which the act is offered, (2) who is involved (party, victim, or witness), and (3) whether extrinsic evidence is being used.

Key Term: Character Evidence
Evidence offered to show a person’s general character or a specific character trait (e.g., honesty, violence), typically to suggest they acted in conformity with that trait on a particular occasion.

Key Term: Specific Instance of Conduct
A concrete prior act or episode from a person’s life (e.g., a prior theft, lying on a form), used as evidence either to prove character or for some other legally permitted purpose.

Key Term: Extrinsic Evidence
Evidence proved through a source other than the witness’s own answers on the stand (such as documents, recordings, or testimony from another witness) to establish a fact independently of the witness’s current testimony.

1. General rule: no specific acts to prove conduct in conformity

Under FRE 404(a)–(b), you generally may not introduce specific instances of conduct to show that someone has a character trait and therefore acted in conformity with that trait on the occasion at issue.

• Example of forbidden use: “He stole before, so he probably stole this time.”
• This prohibition is strongest in civil cases, but also constrains the prosecution in criminal cases.

The examiners love to present fact patterns where a party tries to use prior bad acts simply to show propensity. Unless a specific exception applies, that is inadmissible.

2. Civil cases: character almost never, specific acts almost never

In civil cases, character evidence is usually inadmissible when offered to show conduct in conformity. That means:

• You cannot use specific acts to show “he acted like that again” in ordinary negligence, contract, or strict liability cases.
• This is true regardless of whether the acts are good or bad.

The main exception is when character is itself an essential element of a claim or defense. In those rare civil actions, specific acts are permitted under FRE 405(b).

Examples where character is “in issue”:

• Defamation (truth/falsity of statements about someone’s character).
• Negligent hiring, entrustment, or retention (employer’s knowledge of an employee’s dangerous character).
• Child custody (fitness as a parent, sometimes framed as character).

In those situations, you may prove character by reputation, opinion, and specific instances of conduct, including via extrinsic evidence, because character is directly material.

3. Criminal cases: when specific acts may be used to prove character

Criminal cases have more detailed character rules.

a. The defendant’s character and specific acts

A criminal defendant can choose to “open the door” by offering evidence of a relevant character trait (e.g., peacefulness in an assault prosecution, honesty in a fraud case).

Under FRE 404(a)(2)(A) and 405(a):

• The defendant may offer reputation or opinion evidence of that trait.
• On cross-examination of the defendant’s character witness, the prosecutor may inquire into relevant specific instances of conduct inconsistent with the claimed trait.

Example:

• Defendant calls a character witness: “In my opinion, D is an honest person.”
• On cross, the prosecutor may ask: “Did you know that D filed a false insurance claim last year?”

The prosecution’s questions are allowed to test the basis of the witness’s opinion or knowledge of reputation.

Critical limit: the prosecution may not introduce extrinsic evidence to prove that the specific act actually occurred. If the witness denies knowledge, the examiner is stuck with the answer.

Key Term: Character Witness
A witness who testifies about another person’s character or character trait, usually by reputation or opinion, rather than about the events at issue in the case.

b. The victim’s character and specific acts

In a criminal case, if the defendant offers evidence of the victim’s relevant character trait (e.g., that the victim was violent in a self-defense case), FRE 404(a)(2)(B) allows:

• The defendant to introduce reputation or opinion evidence of the victim’s trait.
• The prosecutor to rebut with reputation or opinion evidence that:
  • The victim has a peaceful character, and/or
  • The defendant has the same violent trait.

On cross-examination of a victim-character witness, the opposing party may inquire into specific instances relevant to the trait, again without extrinsic proof.

c. Sexual assault and child molestation: special specific-act rules

FRE 413–415 create important exceptions:

• In criminal sexual-assault or child-molestation cases, the prosecution may introduce evidence of the defendant’s other sexual assaults or child molestations to show propensity.
• In civil cases involving claims of sexual assault or child molestation, either party may offer similar specific acts of that party.

These are true propensity uses of specific acts—an exception to the normal ban—subject to Rule 403 balancing and advance notice requirements.

Rape-shield rules (FRE 412) sharply limit specific-act evidence of the victim’s sexual behavior or predisposition, with narrow exceptions (e.g., to prove someone else was the source of physical evidence, or in certain fairness situations).

4. Specific acts for non-character purposes: MIMIC/404(b)

The most frequently tested area is FRE 404(b): other crimes, wrongs, or acts offered for a non-character purpose.

Key Term: MIMIC Evidence
Evidence of other crimes, wrongs, or acts offered not to prove character, but to show Motive, Intent, absence of Mistake, Identity (often via a distinctive modus operandi), or Common plan or scheme.

Permissible non-character purposes include:

• Motive (e.g., prior dispute explains why the defendant targeted this victim).
• Intent or knowledge (e.g., prior similar acts show the defendant knew of a scheme or did not act by accident).
• Absence of mistake or accident.
• Identity (especially where the prior act and charged act share a highly distinctive signature).
• Common plan or scheme.

Key points for 404(b)/MIMIC evidence:

• It applies in civil and criminal cases.
• Specific acts may be proved by extrinsic evidence, including witnesses and documents.
• The court must:
  • Ensure a legitimate non-character purpose.
  • Perform Rule 403 balancing (probative value vs unfair prejudice).
  • Give a limiting instruction upon request, telling the jury they may consider the acts only for the permitted purpose (e.g., intent, identity), not to show bad character generally.

Key Term: Non-Character Purpose Evidence
Evidence of specific acts admitted to prove something other than character—for example motive, intent, knowledge, identity, or a common scheme—under FRE 404(b).

5. Impeachment by specific acts: FRE 608(b)

Specific instances of conduct can also be used to attack a witness’s credibility, not to prove what happened in the events at issue in the case.

Key Term: Impeachment by Specific Acts
Attacking a witness’s credibility by inquiring on cross-examination into particular acts that are probative of the witness’s character for truthfulness or untruthfulness, without introducing extrinsic evidence of those acts.

Under FRE 608(b):

• On cross-examination, a party may ask a witness about specific acts if they are probative of truthfulness or untruthfulness (e.g., lying on a tax return, falsifying records, submitting a false insurance claim).
• This applies to any witness, including parties.
• Extrinsic evidence is not allowed solely to prove these acts. If the witness denies the act, the examiner must accept the answer.

This rule is separate from impeachment by conviction under FRE 609, which allows extrinsic proof of certain prior convictions (with its own tests).

The 608(b) limitation is a major MBE trap: you can ask about the act on cross, but you cannot call another witness or produce records solely to prove the act.

6. Habit versus specific acts of character

MBE questions often test whether evidence is truly habit or merely character.

Key Term: Habit Evidence
Evidence of a person’s regular, semi-automatic response to a specific situation (e.g., always checking a mirror before backing up), admissible to prove conduct in conformity on a particular occasion.

Habit (FRE 406):

• Involves specific, repeated, predictable responses to a specific situation (“every time he leaves, he locks the safe”).
• Is admissible to prove conduct in conformity, in both civil and criminal cases, including by specific instances.

Character:

• Is more general (e.g., “careless driver,” “honest person”) and usually not admissible to prove conformity, except under the character rules discussed above.

Distinguish on exam:

• “Always” or “invariably” doing the same thing suggests habit.
• “Often” or “frequently” suggests general character, not habit.

7. Specific acts and hearsay

Specific-act evidence is sometimes presented via out-of-court statements (e.g., “He told me that last year he lied on his tax return”).

• If the statement is offered to prove that the act actually occurred, it is hearsay unless an exception or exclusion applies.
• If the statement is offered for another purpose (e.g., to show the effect on the listener, to show notice, or to impeach), it may be non-hearsay.
• Even when not hearsay, it remains subject to character rules and Rule 403.

Worked Example 1.1

A defendant is on trial for burglary. The prosecution wants to introduce evidence that the defendant committed a similar burglary two years earlier. The defendant has not offered any character evidence.

Answer:
The prosecution cannot use the prior burglary to show that the defendant has a criminal disposition and therefore burglarized again—that would be impermissible propensity evidence. However, if the prior burglary is offered to prove a non-character purpose under 404(b)—for example, identity based on a highly distinctive method (same rare tool, same unusual entry point)—the evidence may be admissible, subject to Rule 403 and a limiting instruction.

Worked Example 1.2

During cross-examination, a witness for the plaintiff is asked, “Isn’t it true that you lied on your tax return last year?” The witness denies it. The cross-examiner seeks to introduce a copy of the tax return and testimony from the IRS agent to prove the lie.

Answer:
Lying on a tax return is a specific instance of conduct probative of truthfulness, so the cross-examiner may ask about it under FRE 608(b). But under 608(b), the examiner may not use extrinsic evidence (the tax return or IRS agent) solely to prove the act. Once the witness denies it, the examiner is bound by that answer and cannot call other witnesses or introduce documents just to show the lie.

Worked Example 1.3

In a civil defamation suit, the defendant newspaper defends by asserting that its statements that the plaintiff is a “habitual fraudster” were true. The newspaper wants to offer evidence that on three prior occasions the plaintiff lied on loan applications and once submitted a fraudulent insurance claim.

Answer:
In a defamation case, the truth of statements about the plaintiff’s character is directly “in issue,” so character is an essential element of a defense. Under FRE 405(b), the defendant may prove the plaintiff’s relevant character trait (dishonesty) by specific instances of conduct, including calling witnesses and offering extrinsic evidence of the prior fraudulent acts. This is one of the rare civil contexts where specific acts may be used affirmatively to prove character.

Worked Example 1.4

In a criminal fraud case, the prosecution offers evidence that the defendant previously engaged in identical fraudulent schemes with different victims, intending to show that he knew the current scheme was fraudulent. The defendant objects that this is propensity evidence.

Answer:
The evidence is admissible under FRE 404(b) as non-character-purpose evidence: it tends to show the defendant’s knowledge and intent, and that the current conduct was not an innocent mistake. The acts may be proved by extrinsic evidence, subject to Rule 403 and a limiting instruction that the jury may not use the acts to infer bad character generally.

Worked Example 1.5

At a robbery trial, the defendant does not testify. He calls a character witness who testifies, “The defendant has a good reputation in the community for honesty.” On cross-examination, the prosecutor asks, “Did you know the defendant stole from his prior employer two years ago?” The witness denies knowledge, and the prosecutor then calls the prior employer to prove the theft.

Answer:
Because the defendant put his character for honesty in issue, the prosecutor may test the character witness’s basis by asking about specific instances inconsistent with that trait—here, theft from the employer. But the prosecutor may not prove the theft with extrinsic evidence (the employer’s testimony) just to impeach the character witness. The employer’s testimony should be excluded on that basis.

Exam Warning

Be careful: The MBE frequently offers answer choices that allow extrinsic evidence of specific acts to impeach a witness’s character for truthfulness. Under FRE 608(b), you may inquire into acts probative of truthfulness on cross-examination, but you may not call another witness or introduce documents solely to prove those acts occurred.

Revision Tip

Remember: In criminal cases, the prosecution cannot introduce specific-act character evidence about the defendant (or victim) to show propensity unless the defendant opens the door or a specific rule (e.g., FRE 413–415) applies. However, the same specific acts may often come in under 404(b) for a non-character purpose, or under 608(b)/609 for impeachment, if the technical requirements are met.

Key Point Checklist

This article has covered the following key knowledge points:

• Specific instances of conduct are generally inadmissible to prove character and action in conformity, especially in civil cases.
• In civil cases, specific acts may be used to prove character only when character is an essential element of a claim or defense (e.g., defamation, negligent hiring).
• In criminal cases, once the defendant offers character evidence, the prosecution may cross-examine character witnesses about relevant specific acts, but may not prove those acts by extrinsic evidence.
• Evidence of other crimes, wrongs, or acts is admissible for non-character purposes (MIMIC: motive, intent, absence of mistake, identity, common plan or scheme) under Rule 404(b), and may be proved by extrinsic evidence subject to Rule 403.
• In sexual assault and child-molestation cases, special rules allow proof of the defendant’s other sexual offenses as propensity evidence, an important exception to the usual ban.
• Impeachment by specific acts under FRE 608(b) allows inquiry on cross-examination into acts probative of truthfulness, but strictly forbids extrinsic evidence offered solely to prove those acts.
• Habit evidence is distinct from character: specific, regular responses to a situation may be used to prove conduct in conformity, even though general character evidence may not.
• Specific-act evidence often overlaps with hearsay; when offered to prove the act occurred, it may raise hearsay issues and must still satisfy character and Rule 403 limits.

Key Terms and Concepts

• Character Evidence
• Specific Instance of Conduct
• Extrinsic Evidence
• Character Witness
• MIMIC Evidence
• Non-Character Purpose Evidence
• Impeachment by Specific Acts
• Habit Evidence