Eyewitness’s subjective certainty of identification is admissible

State v. Guzman, 2006 UT 12

Guzman was the primary participant in a brutal home invasion. The victim identified him in a photo array and a line-up and said she was 100 % certain he was the guy. She was allowed to testify about her certainty at trial, and Guzman was convicted. He claimed on appeal that admitting evidence of an eyewitness’s subjective certainty of identification violates the Due Process clause of the Utah Constitution and rule 403, Utah Rules of Evidence. The supreme court disagreed:

[B]oth our case law and modern sociological research support the admission of testimony concerning an eyewitness’s certainty of identification. A jury ought to be able to consider certainty evidence in determining a witness’s credibility and portrayal of the facts. The jury may then decide, based on the remaining facts, whether the certainty testimony is accurate and truthful. However, we do not require the court or the jury to consider a witness’s level of certainty in determining admissibility or reliability, as indicated by its exclusion from the Long factors. Nevertheless, due process is not violated by permitting the court or the jury to weigh certainty testimony with all other evidence it considers in making necessary determinations.

Justice Durham wrote a concurring opinion in which she agreed with the majority, but added that courts should also be required to issue a cautionary instruction about eyewitness certainty evidence.