Character evidence is admissible in federal court only in limited circumstances. The default under Federal Rule of Evidence 404 is a ban: you cannot offer proof of a person’s character trait to argue they acted in line with that trait on the occasion in dispute.1Legal Information Institute. Federal Rules of Evidence Rule 404 – Character Evidence; Other Crimes, Wrongs, or Acts That default has real teeth, but it also has a long list of exceptions that turn on the type of case, who is offering the evidence, and what the evidence is being used to prove.
The Default Ban on Propensity Evidence
If you are accused of assault, the prosecution cannot call witnesses to testify that you have a bad temper and must have thrown the punch. If you are sued over a car crash, the other driver cannot bring in your friends to say you drive recklessly. Rule 404 keeps the trial focused on what happened on the specific occasion, not on what kind of person the defendant generally is.1Legal Information Institute. Federal Rules of Evidence Rule 404 – Character Evidence; Other Crimes, Wrongs, or Acts
Everything below is an exception to that rule, a different use of character-type evidence that falls outside it, or a boundary that keeps the rule from being read too broadly.
When a Criminal Defendant Can Put Character in Play
The ban loosens in criminal cases, mostly in the defendant’s favor.
The Defendant’s Own Good Character
A defendant may introduce evidence of a relevant good character trait. Someone charged with assault can present witnesses who know them as a peaceful person. Someone charged with fraud can offer evidence of a reputation for honesty. The trait has to match the charge; testimony about generosity does nothing for an assault defense. Once the defendant opens that door, the prosecution can walk through it with rebuttal evidence on the same trait.1Legal Information Institute. Federal Rules of Evidence Rule 404 – Character Evidence; Other Crimes, Wrongs, or Acts
The Alleged Victim’s Character
A criminal defendant can also offer evidence of a relevant trait of the alleged victim. The classic use is self-defense: the defendant argues the victim was the aggressor and backs it with evidence of the victim’s reputation for aggression. If the defense does this, the prosecution gets two responses. It can rebut the evidence about the victim, and it can introduce evidence that the defendant has the same negative trait.1Legal Information Institute. Federal Rules of Evidence Rule 404 – Character Evidence; Other Crimes, Wrongs, or Acts
Homicide cases carry an extra rule. If any evidence suggests the victim was the first aggressor, the prosecution may introduce evidence of the victim’s peaceful character without waiting for the defense to raise the issue.1Legal Information Institute. Federal Rules of Evidence Rule 404 – Character Evidence; Other Crimes, Wrongs, or Acts
Prior Bad Acts for Non-Propensity Purposes
This is where most courtroom fights over character evidence happen. Evidence of other crimes or bad acts cannot come in to show criminal disposition, but it can come in for other purposes: motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake. A prosecutor might offer evidence of a prior fraud to show the defendant knew how a particular scheme worked, not to argue the defendant is a fraudster by nature.1Legal Information Institute. Federal Rules of Evidence Rule 404 – Character Evidence; Other Crimes, Wrongs, or Acts
The line between propensity and a permitted purpose is often razor-thin. Even when a permitted purpose exists, the judge can still exclude the evidence under Rule 403 if the risk of unfair prejudice substantially outweighs the probative value.2Legal Information Institute. Federal Rules of Evidence Rule 403 – Excluding Relevant Evidence for Prejudice, Confusion, Waste of Time, or Other Reasons That balancing is the main check against prior-act evidence sneaking in as backdoor propensity proof.
A prosecutor who plans to use prior bad act evidence in a criminal case must give the defendant reasonable written notice before trial. The notice must identify the evidence, state the permitted purpose, and explain the reasoning behind that purpose. A court can excuse the lack of pretrial notice for good cause.1Legal Information Institute. Federal Rules of Evidence Rule 404 – Character Evidence; Other Crimes, Wrongs, or Acts
Civil Cases: A Narrower Opening
In civil cases, the propensity ban applies more strictly. A plaintiff in a negligence case cannot call witnesses to testify about how careful they usually are. The defendant cannot offer character proof to argue it probably did the right thing.
The one real opening is when character itself is an essential element of a claim or defense. Here the evidence is not being used circumstantially at all; it is direct proof of something the party has to establish. Defamation is the clearest example, because the plaintiff’s reputation is literally what was allegedly harmed. Negligent entrustment is another: if you lent your car to someone you knew was reckless, the borrower’s recklessness is a required part of the plaintiff’s case.1Legal Information Institute. Federal Rules of Evidence Rule 404 – Character Evidence; Other Crimes, Wrongs, or Acts Child custody disputes can also put character directly at issue, since a parent’s fitness is the question before the court.
Sexual Offense Cases: The Rules Flip
Congress created a separate framework for sexual offense cases that departs sharply from the general ban.
In a criminal case involving sexual assault, the court may admit evidence that the defendant committed any other sexual assault, and the jury may consider it for any relevant purpose, including propensity. The same rule applies to child molestation cases.3Court Rules Network. Rule 413 – Similar Crimes in Sexual-Assault Cases4Legal Information Institute. Federal Rules of Evidence Rule 414 – Similar Crimes in Child Molestation Cases The prosecutor must disclose the evidence to the defendant at least 15 days before trial, including witness statements or a summary of expected testimony, unless the court extends the deadline for good cause. The same framework reaches civil claims based on sexual assault or child molestation.5Court Rules Network. Rule 415 – Similar Acts in Civil Cases Involving Sexual Assault or Child Molestation
The door opens on the defendant’s past and shuts on the victim’s. Rule 412, often called the rape shield rule, prohibits evidence of an alleged victim’s past sexual behavior or sexual predisposition in both criminal and civil proceedings involving sexual misconduct. Criminal cases allow narrow exceptions: specific instances to show someone other than the defendant was the source of physical evidence, prior sexual conduct between the victim and the defendant where consent is at issue, and evidence whose exclusion would violate the defendant’s constitutional rights. In civil cases, the evidence comes in only if its probative value substantially outweighs both the danger of harm to the victim and the risk of unfair prejudice. A party who wants to use any of these exceptions must file a written motion at least 14 days before trial, notify the victim, and go through a closed hearing before the court rules.6Legal Information Institute. Federal Rules of Evidence Rule 412 – Sex-Offense Cases: The Victim
Witness Credibility Is a Separate Track
Character evidence works differently when the target is a witness rather than a party. Either side can attack a witness’s credibility with testimony about the witness’s reputation for being untruthful, or with an opinion about the witness’s honesty. Evidence that a witness is truthful is admissible only after someone has attacked the witness’s character for truthfulness; you cannot bolster preemptively.7Legal Information Institute. Federal Rules of Evidence Rule 608 – A Witness’s Character for Truthfulness or Untruthfulness
Criminal convictions can also be used to undermine credibility. Convictions for crimes involving dishonesty or false statements are admissible regardless of the severity of the punishment. For other crimes punishable by more than a year of imprisonment, the conviction is admissible in civil cases subject to Rule 403 balancing. When the witness is the defendant in a criminal case, the standard is stricter: the conviction comes in only if its probative value outweighs the prejudice to the defendant.8Legal Information Institute. Federal Rules of Evidence Rule 609 – Impeachment by Evidence of a Criminal Conviction
Habit Is Not Character
People sometimes assume habit evidence falls under the same ban. It does not. Character is a general disposition, such as being careful or honest. Habit is a specific, nearly automatic response to a particular situation, such as always signaling before a left turn or always locking the office door on the way out. Habit evidence is freely admissible to prove someone acted consistently with the habit on a given occasion, and routine practice of an organization works the same way. No corroboration is required, and the absence of eyewitnesses does not matter.9Legal Information Institute. Federal Rules of Evidence Rule 406 – Habit; Routine Practice
How Admissible Character Evidence Gets Proved
When character evidence is admissible, the method depends on why it is being offered. When it is used circumstantially, such as a defendant presenting a good character trait, proof is limited to reputation testimony and opinion testimony. A witness might describe the defendant’s reputation for honesty in the community, or give a personal opinion based on their own dealings with the defendant.10Legal Information Institute. Federal Rules of Evidence Rule 405 – Methods of Proving Character
Specific instances of conduct are generally off-limits in that circumstantial use. But on cross-examination, the opposing lawyer can ask a character witness about specific incidents to test whether the witness actually knows what they are talking about. A question like “Did you know the defendant was fired for stealing from a previous employer?” is not offered to prove the theft; it probes whether the glowing opinion is well-founded.10Legal Information Institute. Federal Rules of Evidence Rule 405 – Methods of Proving Character
When character is an essential element of a claim or defense, all three methods are available: reputation, opinion, and specific instances of conduct.10Legal Information Institute. Federal Rules of Evidence Rule 405 – Methods of Proving Character
Limiting Instructions When It Does Come In
When a court admits evidence for a limited purpose, either side can ask the judge to instruct the jury to consider it only for that purpose. Under Rule 105, the court must give such an instruction when requested.11Legal Information Institute. Federal Rules of Evidence Rule 105 – Limiting Evidence That Is Not Admissible Against Other Parties or for Other Purposes This happens constantly with prior bad act evidence. A typical federal model instruction tells jurors they “may not consider this evidence as proof that the defendant has a bad character or any propensity to commit crimes” and may not “conclude that because the defendant may have committed the other act, he must also have committed the act charged.”12Ninth Circuit District & Bankruptcy Courts. Other Crimes, Wrongs or Acts of Defendant Failing to request the instruction when the evidence comes in generally waives the issue on appeal.