Explain FRE 404 and 405 and how they work together

Direct Answer: Federal Rules of Evidence (FRE) 404 and 405 govern when and how character evidence may be admitted at trial. Rule 404 determines whether character evidence is admissible at all, while Rule 405 governs the methods by which admissible character evidence may be proven. Together, they prevent unfair prejudice by restricting the use of character evidence to infer conduct, while permitting limited, controlled uses when character is legitimately in issue or otherwise relevant.

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I. Issue

How do Fed. R. Evid. 404 and Fed. R. Evid. 405 operate—individually and together—in determining both the admissibility and method of proving character evidence?

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II. Rule

Rule 404 – Admissibility of Character Evidence

Rule 404(a) generally prohibits evidence of a person’s character to prove that they acted in conformity with that character on a particular occasion. It provides three primary exceptions:

1. Character of the accused – The defendant may offer evidence of a pertinent character trait, and the prosecution may rebut it.
2. Character of the victim – The defendant may offer evidence of the victim’s pertinent trait (commonly in self-defense), and the prosecution may rebut it.
3. Character of a witness – Governed under Fed. R. Evid. 607, Fed. R. Evid. 608, and Fed. R. Evid. 609.[2][3]

Rule 404(b) further prohibits “other crimes, wrongs, or acts” to prove propensity, allowing them only for other purposes such as motive, opportunity, intent, or absence of mistake.[2]

Rule 405 – Methods of Proving Character

Once a court determines under Rule 404 that character evidence is admissible, Rule 405 prescribes how it can be proved:

1. Rule 405(a) allows proof by reputation or opinion testimony. On cross-examination, the opposing party may inquire into specific instances of conduct.
2. Rule 405(b) allows proof by specific instances of conduct only when character is an essential element of a claim, charge, or defense (i.e., “character in issue”).[1][5]

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III. Application / Relationship Between Rules 404 and 405

Rule 404 gates admissibility, while Rule 405 defines form and proof once admissible. Courts apply these Rules sequentially:

1. Step 1 – Admissibility under Rule 404: The judge first determines whether the offered character evidence fits one of the 404(a) exceptions or serves a permissible non-propensity purpose under 404(b).
2. Step 2 – Method under Rule 405: If admissible, the proponent may introduce it only via reputation or opinion testimony. Specific instances are admissible only when character itself is an element of the case (e.g., defamation, negligent entrustment, or entrapment defense).[1][4]

For example, in United States v. Keiser, 57 F.3d 847 (9th Cir. 1995), the Ninth Circuit emphasized that the trial court must determine admissibility under Rule 404 before turning to Rule 405 to decide the proper method of proof.[1]

In self-defense cases, defendants can use Rule 404(a)(2) to show the victim’s violent character through opinion or reputation evidence under Rule 405(a). Once introduced, the prosecution may rebut or cross-examine on specific instances of conduct to test credibility.[4]

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IV. Conclusion

Rules 404 and 405 form a two-step framework: Rule 404 controls whether character evidence may be admitted at all, and Rule 405 limits how that evidence is presented once admissible. This interplay balances probative value against prejudice, ensuring fairness while allowing relevant character evidence in legally permissible circumstances.

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