Why should a jury consider base-rate probabilities when evaluating eyewitness testimony?

It is a common misconception that eyewitness testimony is inherently reliable; in fact, research shows it is often prone to error and has been a leading cause of wrongful convictions.1

When evaluating such testimony, a jury should consider base-rate probabilities to avoid the base-rate fallacy, a logical error where one focuses on specific evidence (the witness's identification) while ignoring the broader statistical context (the actual probability of a suspect being guilty).

In the context of logic and fallacies, relying solely on an eyewitness ignores the reality that identification procedures can be influenced by factors like stress, weapon focus, or suggestive police practices. By considering base rates—such as the likelihood of a random person in a lineup being the perpetrator versus the probability of a witness making a mistake—a jury can better weigh the evidence. Ethical justice requires that we prioritize objective accuracy over the subjective confidence of a witness, especially given that procedural reforms have been necessary to mitigate the high risk of human error in criminal identification.1