State v. Guzman

¶1concurring:

¶2¶30 I agree with the majority’s holding that the admission of eyewitness certainty testimony does not violate the Due Process Clause of the Utah Constitution. However, I would add that, upon request, a defendant is entitled to a cautionary instruction summarizing the troublesome nature of certainty testimony and explaining that it is only one indicator of witness accuracy. Requiring this type of instruction addresses the potential dangers of certainty testimony, such as the risk that witness confidence may be influenced by intentional or inadvertent clues from law enforcement, may be conflated by positive feedback, or may be afforded too much weight by a jury.1See Gary L. Wells et al., Eyewitness Identification Procedures: *370Recommendations for Lineups and Photospreads, 22 Law & Hum. Behav. 603, 620-29 (1998). This instruction is also consistent with research suggesting that witness confidence is not necessarily an indicator of witness accuracy. See id. at 620-21, 626 (citing studies finding that confidence and accuracy were either not related or only somewhat related and concluding that, at best, confidence is “only modestly related to accuracy under pristine conditions”); Steven Penrod & Brian Cutler, Witness Confidence and Witness Accuracy: Assessing Their Forensic Relation, 1 Psychol. Pub. Pol’y & L. 817, 830 (1995) (noting that witness confidence “is a weak indicator of eyewitness accuracy even when measured at the time an identification is made and under relatively ‘pristine’ laboratory conditions” and is “highly malleable and influenced by postidentification factors” such as questioning, briefing, and feedback).

¶3¶ 31 Moreover, I believe our reasoning in State v. Long, 721 P.2d 483 (Utah 1986), supports the addition of a cautionary instruction in cases with certainty evidence. In Long, this court recognized that there are “deep and generally unperceived flaws” in eyewitness identifications and held that additional instruction is necessary where jurors are likely to give great weight to eyewitness testimony. Id. at 492. While Longdealt exclusively with eyewitness identification, see id.,the policy this court expressed applies to certainty evidence because, like eyewitness identification, it is potentially unreliable2 and there is evidence that jurors afford it great weight, see Wells et al., supra ¶30, at 620, 626. I therefore conclude that where certainty testimony is admitted, a cautionary instruction should be given where the defendant requests one.