What Is 404b Evidence And When Is It Admissible?
404b evidence refers to evidence of other crimes, wrongs, or acts introduced in a trial to prove something other than a person’s character or propensity to commit the crime charged. It gets its name from Federal Rule of Evidence 404b, which governs the admissibility of this type of evidence.
Common Defenses Against 404b Evidence
Defense attorneys have several arguments available to exclude 404b evidence:
- The evidence shows propensity only, not a proper 404b purpose
- The prior acts are too dissimilar, remote in time, or irrelevant
- The prejudicial effect substantially outweighs any probative value
- No proper limiting instruction can cure the prejudice
- The evidence would confuse the issues or mislead the jury
By focusing on these potential weaknesses, the defense may convince the judge to exclude some or all 404b evidence.
Examples of 404b Issues
404b evidence often plays a prominent role in criminal trials. Here are some real-world examples:
- In a fraud prosecution, the government sought to introduce evidence of the defendant’s prior convictions for mail fraud under 404b to show knowledge and intent. The trial judge excluded the evidence as too prejudicial since the prior frauds were not sufficiently similar. United States v. Garcia-Toro
- In a drug conspiracy case, the trial court allowed 404b evidence of the defendant’s prior involvement in the drug trade to show his intent, knowledge, and absence of mistake in joining the charged conspiracy. The appeals court affirmed the ruling. United States v. LaFlam
- In a prosecution for being a felon in possession of a firearm, the government sought to introduce the defendant’s two prior felony convictions involving firearm possession to show knowledge and absence of mistake. The trial court excluded the evidence under 403, finding the risk of unfair prejudice outweighed its probative value. United States v. Caldwell
- In a murder case, the trial court admitted evidence of the defendant’s previous assault against the victim under 404b to establish motive and intent. The appeals court found this was proper and relevant to rebut the defendant’s claim of self-defense. People v. Spector
As these examples show, application of the 404b rule often leads to close calls over whether the probative value justifies admission despite the risk of unfair prejudice. Careful argument by counsel over these balancing issues is key.
- Prosecutors should articulate the proper 404b purpose and reasoning for admission and be prepared to defend the relevance and probative value versus prejudice.
- Defense counsel should scrutinize any 404b evidence for grounds to exclude it, such as lack of similarity, remoteness in time, and potential to confuse or mislead the jury.
- Both sides should research the applicable case law in their jurisdiction on 404b admissibility standards. Precedent varies across circuits.
- For admitted 404b evidence, request a clear limiting instruction from the judge explaining the permissible and prohibited uses. Object to any instruction that is vague or confusing.
- The judge should hold a hearing outside the jury’s presence before trial to carefully consider 404b admissibility issues. This avoids tainting the jury with potentially inadmissible evidence.
- Appellate courts review 404b rulings for abuse of discretion, a deferential standard, so trial judges have latitude in weighing relevance versus prejudice.
404b evidence can strengthen the prosecution’s case but also risks unfair prejudice. Careful application of the rules of evidence and persuasive advocacy are key to successfully navigating 404b issues at trial. The judge serves as gatekeeper, deciding whether the proper purpose, relevance, and probative value justify admission of a defendant’s other crimes, wrongs, or acts.