Character Evidence and Rule 404(b) Explained (1L Evidence)

Rule 404 states the propensity prohibition: evidence of a person's character or character trait is not admissible to prove that on a particular occasion the person acted in accordance with that character. The concern is not that such evidence is irrelevant. It is that juries overweight it and may punish the defendant for who they are rather than for what they did.

The rule is a prohibition on a specific chain of inference, not on a category of facts. The same evidence that is inadmissible to show "he is a violent person, so he probably attacked the victim" may be perfectly admissible to show identity, motive, or knowledge.

So the analytical question in every character evidence problem is never "is this character evidence?" It is "what is this evidence being offered to prove, and does the path from the evidence to that conclusion run through propensity?"

Rule 404(a)(1) contains the general prohibition. It applies in both civil and criminal cases.

Rule 404(a)(2) contains the exceptions, and they apply only in criminal cases. A defendant may offer evidence of their own pertinent character trait, and if they do, the prosecution may rebut it. This is sometimes called the mercy rule, and the key feature is that the defendant controls the door: the prosecution cannot introduce the defendant's character until the defendant opens it.

A defendant may also offer evidence of an alleged victim's pertinent trait — for instance, the victim's violent character in a self-defense case. Doing so has two consequences. The prosecution may rebut with evidence of the victim's good character for that trait, and it may also offer evidence of the same trait in the defendant. That second consequence surprises students and is a common exam trap.

There is a narrower homicide provision as well: where the defendant claims the victim was the first aggressor, the prosecution may offer evidence of the victim's peaceful character to rebut that claim, whether or not the defendant offered character evidence.

Rule 404(a)(3) points to the witness-character rules — Rules 607, 608, and 609 — which govern impeachment and operate on a different logic, since there the character at issue is truthfulness rather than conduct on the occasion in question.

Rule 404(b)(1) restates the prohibition for crimes, wrongs, and other acts. Rule 404(b)(2) then provides that such evidence may be admissible for another purpose, and lists examples: motive, opportunity, intent, preparation, plan, knowledge, identity, absence of mistake, and lack of accident.

The list is illustrative rather than exhaustive, and the common mnemonic MIMIC captures the most tested items — motive, intent, mistake (absence of), identity, and common plan or scheme.

Two points about how this actually works. First, the evidence still must clear Rule 403; a permitted purpose gets the evidence past 404(b) but a court may still exclude it if the danger of unfair prejudice substantially outweighs its probative value. This is where most real litigation happens.

Second, the permitted purpose must be genuinely at issue. Offering a prior fraud conviction to prove intent is only meaningful if intent is contested. If the defendant's entire defense is that they were not present, intent is not in dispute, and the intent rationale is a pretext for propensity.

In criminal cases the prosecution must give notice: on request, it must articulate in writing the permitted purpose for which it intends to offer the evidence and the reasoning supporting it, before trial or during trial for good cause. That notice requirement is testable and easy to overlook.

Rule 405 is the rule students most often skip, and it decides a large share of exam questions. Even where character evidence is admissible, the method of proof is restricted.

The general method is reputation or opinion testimony. A witness may testify to the person's reputation in the community, or state their own opinion of the person's character.

Specific instances of conduct are generally not permitted on direct examination, but they are permitted on cross-examination of a character witness. The theory is that specific acts test whether the witness actually knows what they claim to know. Crucially, the cross-examiner must have a good-faith basis for the question and is bound by the answer — no extrinsic evidence may be introduced to prove the specific act occurred.

The exception is Rule 405(b): where a person's character or trait is an essential element of a charge, claim, or defense, specific instances may be proved on direct. This is a narrow category. The standard examples are defamation, where the plaintiff's reputation is itself the subject of the claim; negligent entrustment or negligent hiring, where the entrusted person's incompetence is an element; and entrapment, where the defendant's predisposition is an element.

Rule 406 admits evidence of a person's habit or an organization's routine practice to prove conduct in conformity on a particular occasion. It may be admitted regardless of corroboration and regardless of whether there was an eyewitness.

That is the opposite of the character rule, so the boundary matters. Character is a general propensity — carefulness, honesty, violence. Habit is a specific, regular, near-automatic response to a specific repeated situation.

"He is a careful driver" is character and inadmissible to prove careful driving on the day in question. "He stopped at that particular intersection every morning for eleven years" is habit and admissible. The distinguishing features are specificity of the situation, regularity of the response, and the absence of deliberation.

Business routine works the same way and is often easier to establish, since organizations tend to have documented practices. Evidence that a company always mails a notice on the first business day of the month is routine-practice evidence, admissible to show it did so in the month at issue.

Rules 413, 414, and 415 create genuine propensity exceptions in cases involving sexual assault and child molestation. In such cases the court may admit evidence that the defendant committed other offenses of the same kind, and the evidence may be considered on any matter to which it is relevant — including propensity.

This is a real departure from the structure of Rule 404, and courses flag it because it is the clearest legislative exception to the propensity ban. Rule 403 continues to apply, and courts have used it actively in this area.

Rule 412, the rape shield rule, runs in the other direction. It restricts evidence of an alleged victim's other sexual behavior or sexual predisposition, with limited exceptions that differ between criminal and civil cases. In criminal cases these include specific instances offered to prove that someone else was the source of physical evidence, specific instances with the accused offered on consent, and evidence whose exclusion would violate the defendant's constitutional rights.

Note the asymmetry the two rules create, since exams sometimes ask about it directly: the defendant's prior sexual offenses become more admissible while the complainant's sexual history becomes less so.

Asking whether evidence "is character evidence" rather than what it is offered to prove. The same testimony can be barred for one purpose and admitted for another in the same trial, sometimes with a limiting instruction under Rule 105.

Forgetting that Rule 403 still applies. A 404(b) purpose is a gateway, not a guarantee. Strong answers identify the permitted purpose and then weigh probative value against unfair prejudice.

Missing the second consequence of attacking the victim's character. When a defendant offers evidence of the victim's violent character, the prosecution may respond with evidence of the defendant's character for the same trait — not only with evidence about the victim.

Allowing specific instances on direct examination. Unless character is an essential element under Rule 405(b), specific acts come in only on cross, and the cross-examiner cannot prove them up with extrinsic evidence.

Treating a general disposition as habit. Courts require specificity and regularity, and a witness's characterisation of someone as generally careful or generally punctual will not carry Rule 406.

Verbloom's law-school module includes evidence problems that ask you to identify the purpose for which an item is offered before ruling on admissibility, which mirrors how these questions are actually structured on exams.

Character evidence rewards that ordering specifically: the purpose determines the rule, the rule determines the permitted method of proof, and getting those in the wrong order produces confident wrong answers.