People v. Lemcke, 486 P.3d 1077

Defendant Charles Rudd was convicted of robbery and assault largely on the victim Monica Campusano’s eyewitness identification; Campusano identified Rudd from a hospital photographic lineup (while medicated) and again in court.
The trial court instructed the jury with CALCRIM No. 315, which lists 15 factors to evaluate eyewitness ID, including: “How certain was the witness when he or she made an identification?”
Defense presented expert testimony (Dr. Eisen) explaining the weak general correlation between witness confidence and accuracy, the commitment effect, and that confidence is most predictive only when given immediately after a fair, nonsuggestive lineup.
Trial court refused to strike the certainty factor; jury convicted; Court of Appeal affirmed based on prior California authority; Supreme Court granted review on whether the certainty instruction violated due process.
Supreme Court affirmed the conviction (no federal/state due process violation given the instructions and record, and the defendant’s opportunity to present expert evidence), but acknowledged near‑unanimous empirical findings that confidence is generally unreliable and (exercising supervisory power) directed Judicial Council review and ordered trial courts to omit the certainty factor from CALCRIM No. 315 pending that review unless a defendant requests it.

Issue	Plaintiff's Argument (People)	Defendant's Argument (Rudd)	Held
Whether CALCRIM No. 315’s certainty factor violated due process by prompting jurors to equate certainty with accuracy and thereby lowering the prosecution’s burden	Instruction is facially neutral; jury may weigh all factors; expert testimony and other instructions guard against misapplication; no burden shift	The certainty factor implies certainty = accuracy, misleads jurors, lowers burden, and undermines defendant’s ability to present a complete defense	No due process violation: when viewed with the whole charge and record (including expert testimony and reasonable‑doubt instructions) the factor did not render the trial fundamentally unfair
Whether courts should alter or remove the certainty factor going forward	Improvements may be appropriate but should proceed via Judicial Council rulemaking and public comment; supervisory action is unnecessary	Amici/Rudd: strike the factor or require an enhanced instruction that summarizes empirical research	Court referred issue to Judicial Council for reevaluation and, exercising supervisory power, directed trial courts to omit the certainty factor from CALCRIM No. 315 until revised (but courts may include it if defendant requests)

People v. Sánchez, 63 Cal.4th 411 (Cal. 2016) (approved use of a similar certainty factor; noted instruction is facially neutral)
People v. Johnson, 3 Cal.4th 1183 (Cal. 1992) (upheld CALJIC identification instruction including certainty language)
People v. Wright, 45 Cal.3d 1126 (Cal. 1988) (approved CALJIC No. 2.92 factors for eyewitness ID)
People v. McDonald, 37 Cal.3d 351 (Cal. 1984) (recognized value of expert testimony on eyewitness reliability)
Cupp v. Naughten, 414 U.S. 141 (U.S. 1973) (instruction that a witness is presumed to tell the truth did not violate due process when read in context with reasonable‑doubt instructions)
State v. Henderson, 27 A.3d 872 (N.J. 2011) (surveyed eyewitness research; concluded confidence is generally an unreliable indicator of accuracy and adopted modified model charge)
Commonwealth v. Gomes, 22 N.E.3d 897 (Mass. 2015) (convened study; concluded jurors overvalue confidence and adopted model instruction addressing confidence)
State v. Lawson, 291 P.3d 673 (Or. 2012) (reviewed research showing jurors overweight confidence and discussed instruction reform)