Character Evidence as a Conduit for Implicit Bias

The Federal Rules of Evidence purport to prohibit character evidence, or evidence regarding a defendant’s past bad acts or propensities offered to suggest that the defendant acted in accordance with a certain character trait on the occasion in question. However, courts regularly admit character evidence through an expanding set of legislative and judicial exceptions that have all but swallowed the rule. In the usual narrative, character evidence is problematic because jurors place excessive weight on it or punish the defendant for past behavior. Lawmakers rely on this narrative when they create exceptions. However, this account arguably misses a highly troublesome feature of character evidence and far understates its pernicious effects. In this Article, I develop a new model of character evidence that refocuses the debate on the distortions associated with the prior beliefs and prejudices inherent in a juror’s perception of character evidence. Specifically, I draw on disciplines outside of law — including Bayesian statistics and cognitive psychology — to explain how jurors use character evidence to arrive at a verdict. I then apply this framework to show that when a court admits character evidence through exceptions, judgments based on character evidence are inherently biased against certain groups of people based on their race, sex, appearance, accent, education, economic status, and other personal characteristics. I argue that exceptions to the rule against character evidence therefore drive inequality in the U.S. legal system, and that this provides a strong reason to limit such exceptions and to reverse the current trend toward a more permissive rule