UC San Diego

Eyewitness misidentifications have contributed to many wrongful convictions. However, despite expressing high confidence at trial, eyewitnesses often make inconclusive misidentifications on the first test conducted early in a police investigation. According to a new scientific consensus, it is important to focus on the results of the first test because, if the perpetrator is not in the lineup, the test itself leaves a memory trace of the innocent suspect in the witness’s brain. Thus, all subsequent tests of the witness’s memory for the same suspect constitute tests of contaminated memory. Unfortunately, when evidence of an initial inconclusive identification is introduced at trial, the rules of evidence provide a witness with an opportunity to explain their prior inconsistent statement. In response, witnesses often provide an opinion about why they did not confidently identify the suspect on the initial test despite doing so now (e.g., “I was nervous on the first test”).However, witnesses lack expertise in—and have no awareness of—the subconscious mechanisms of memory contamination that have been elucidated by decades of scientific research. The combination of a sincerely held (false) memory and a believable (but erroneous) explanation for a prior inconsistent statement is often persuasive to jurors. This is a recipe for a wrongful conviction, one that has been followed many times. The Federal Rules of Evidence were enacted almost a half-century ago, and it maybe time to revisit them in light of the principles of memory that have been established since that time.