People v. Herrera
202 Cal. Rptr. 3d 187
| Cal. Ct. App. | 2016Background
- Defendant Richard Arce Herrera stabbed and killed his friend Bobby Khamvongsa; Herrera admitted the killing and was convicted of first degree murder with a true weapon-use allegation.
- Herrera had a long history of childhood sexual abuse and diagnosed PTSD; he sought to present expert psychiatric testimony that PTSD and a peritraumatic dissociative state affected his mental condition the night of the killing.
- The trial court permitted general PTSD testimony and testing results but prohibited the expert from testifying about Herrera’s mental state “at the time of the offense” or otherwise about his psychiatric condition on the day of the killing.
- Defense argued exclusion violated Herrera’s federal constitutional right to present a complete defense; prosecution relied on Penal Code §§ 28–29 and controlling precedent to bar expert testimony about the defendant’s mental state as to elements like intent, premeditation, deliberation, or malice.
- The Court of Appeal held the exclusion was unduly restrictive under controlling authority (notably People v. Cortes) and prejudicial because Herrera’s only plausible defense to premeditated murder depended on psychiatric evidence about his state during the assault; judgment reversed.
Issues
| Issue | Plaintiff's Argument (Herrera) | Defendant's Argument (People/Respondent) | Held |
|---|---|---|---|
| Whether the trial court erred by barring expert testimony about defendant’s psychiatric condition at the time of the killing | Excluding testimony that Herrera suffered PTSD/dissociation on the day of the killing denied his right to present a defense and prevented the jury from inferring lack of premeditation or malice | Sections 28–29 and cases like Pearson bar experts from testifying whether defendant had or lacked the specific mental state required for the crime; the court properly kept such testimony out | Reversed: court abused discretion by broadly excluding testimony about defendant’s mental condition at the time of the offense; such evidence is admissible so long as the expert does not directly opine on the legal ultimate issue; error was prejudicial |
| Scope of admissible expert testimony about mental disorder and its relation to criminal intent | Expert may testify about diagnoses, symptoms, and how those conditions affected defendant at the time of the offense, permitting the jury to draw reasonable inferences about intent | Permissible testimony must not be tantamount to stating the defendant did or did not form the required legal mental state | Held that sections 28–29 allow expert testimony on diagnoses and peritraumatic states and their effects, but not explicit opinions on the ultimate legal mental-state element |
| Prejudice standard — whether error was harmless | Exclusion eviscerated Herrera’s defense to premeditation/deliberation and impaired jury’s ability to assess self-defense/heat-of-passion; reversal required under Watson standard | Evidence of planning, multiple stab wounds, flight, and purchase of knife support first degree murder; any limiting instruction or other evidence made error harmless | Court found prejudice reasonably probable; reversal warranted |
| Interaction of Pearson and Cortes — proper boundary of expert testimony | Cortes allows extensive testimony about dissociation/PTSD and its effects on behavior; Herrera’s expert should have been allowed to testify similarly | Pearson prohibits expert testimony that effectively answers the ultimate question of premeditation/deliberation; trial court followed Pearson | Court reconciled Pearson and Cortes: Pearson forbids direct opinion on legal state, but Cortes allows expert opinions about diagnoses and peritraumatic states that permit jury inference; exclusion here exceeded permissible limits |
Key Cases Cited
- People v. Coddington, 23 Cal.4th 529 (Cal. 2000) (sections 28–29 permit expert testimony on mental disorder but bar experts from stating ultimate legal mental-state conclusions)
- People v. Cortes, 192 Cal.App.4th 873 (Cal. Ct. App. 2011) (trial court abused discretion by excluding expert testimony that defendant was dissociated or had PTSD at time of offense; such testimony may be admissible to show condition and its effects)
- People v. Pearson, 56 Cal.4th 393 (Cal. 2013) (expert may not be asked to provide an opinion that directly resolves premeditation/deliberation; court may exclude questions seeking ultimate legal mental-state opinion)
- People v. Watson, 46 Cal.2d 818 (Cal. 1956) (standard for prejudicial error: reversal required when it is reasonably probable defendant would have obtained a more favorable result but for the error)
- People v. Halvorsen, 42 Cal.4th 379 (Cal. 2007) (discussion of limits on expert testimony about defendant’s mental state and the risk of testimony functioning as the legal conclusion)