People v. Stevens, 62 Cal. 4th 325

MDO Act permits civil commitment of parolees with a severe mental disorder meeting set criteria (§2962, subd. (d)(1)); certification by chief psychiatrist triggers Board hearing to assess commitment.
As part of MDO proceedings, the inmate previously committed for petty theft with a prior and alleged threats of force/violence; the qualifying offense is under §2962, subd. (e)(2)(Q).
Dr. Kevin Perry, a psychologist, testified that Stevens had a severe mental disorder (schizophrenia, undifferentiated type) and that the disorder was an aggravating factor in the offense, basing his opinion partly on relied-upon records and probation reports.
The prosecutor sought to base the “force or violence” element on hearsay from records; objection raised but some testimony was admitted without a ruling, and the court treated it as producing substantial evidence.
Court of Appeal affirmed, holding that experts may rely on hearsay documents to support an opinion under Evidence Code 801(b), but the Supreme Court later disapproved Miller’s broad admissibility of such hearsay as independent proof of the offense and required proof of the underlying facts by proper means.
The Supreme Court reversed the Court of Appeal and held that, in MDO proceedings, the People may not prove the facts underlying the commitment offense through mental health expert opinion testimony, and that documentary/historical evidence cannot be supplanted by expert testimony for the underlying offense.

Issue	Plaintiff's Argument	Defendant's Argument	Held
May a mental health expert's opinion serve as independent proof of a qualifying MDO offense?	Stevens argues expert reliance on records suffices.	Stevens argues expert should not prove underlying offense.	No; expert opinion cannot independently prove the offense.
May expert testimony describe threats/force in committing the offense based on records?	People rely on expert to connect disorder to offense.	Defense contends such testimony is inadmissible as factual proof.	No; such testimony cannot prove the underlying facts of the offense.
Is Miller still valid versus Baker on admissibility of hearsay in MDO trials?	Miller permits expert to rely on hearsay for basis of opinion.	Baker rejects using expert to prove offense facts via hearsay.	Court disapproves Miller’s broad use; rejects Baker’s limitations for independent proof.

People v. Miller, 25 Cal.App.4th 913 (Cal. Ct. App. 1994) (expert may rely on probation reports; hearsay not independent proof of facts)
People v. Baker, 204 Cal.App.4th 1234 (Cal. Ct. App. 2012) (expert testimony cannot prove underlying facts of the offense; not independent proof)
People v. Sheek, 122 Cal.App.4th 1606 (Cal. Ct. App. 2004) (MDO procedures and evidentiary standards)
People v. Harrison, 57 Cal.4th 1211 (Cal. 2013) (MDO Act procedural vs. substantive distinctions; public safety goals)
People v. Cosgrove, 100 Cal.App.4th 1266 (Cal. Ct. App. 2002) (civil MDO proceedings; discovery and procedure)