California Legal Brief

The Rule of Joel Praneet Siam is that when determining whether a defendant's symptoms would respond to treatment under Penal Code section 1001.36(c)(1), a trial court may not override a qualified mental health expert's opinion with its own lay opinion about treatment responsiveness, under circumstances where a licensed psychologist provides an uncontroverted expert opinion that the defendant's mental disorder symptoms would respond to treatment.

Appeal from order denying pretrial mental health diversion motion in Superior Court, Orange County.

Petitioner was Joel Praneet Siam — a defendant diagnosed with bipolar disorder, generalized anxiety disorder, and panic disorder who sought pretrial mental health diversion after being charged with stealing a yacht and damaging property while in a manic episode.

Respondent was The Superior Court of Orange County — the trial court that denied Siam's mental health diversion motion based on findings regarding treatment responsiveness and dangerousness.

The suit sounded in criminal law seeking pretrial mental health diversion. Real party in interest The People opposed the motion.

The key substantive facts leading to the suit were Siam committed two offenses while experiencing mental health episodes: in August 2020, he struck a taxi driver with a skateboard and was found naked in a hotel elevator acting erratically; in March 2022, while on mental health diversion for the first offense, he damaged a Rolls Royce at a dealership and stole a yacht, crashing it into boats and injuring a woman. A licensed psychologist diagnosed him with bipolar disorder and opined his symptoms would respond to treatment, but the trial court rejected this expert opinion based on what it perceived as Siam's history of treatment noncompliance.

The procedural result leading to the Appeal: The trial court denied Siam's mental health diversion motion, ruling that he was eligible but not suitable because his symptoms would not respond to treatment and he posed an unreasonable risk of danger to public safety.

The key question(s) on Appeal: 1. Whether the trial court abused its discretion by rejecting a qualified mental health expert's opinion that defendant's symptoms would respond to treatment based on the court's own assessment of treatment compliance history. 2. Whether substantial evidence supported the trial court's finding that defendant posed an unreasonable risk of danger to public safety.

The Appellate Court held the trial court abused its discretion by applying the wrong legal standard when it effectively overrode the uncontroverted opinion of a qualified mental health expert regarding treatment responsiveness, and by making dangerousness findings not supported by substantial evidence, including erroneous findings about defendant's treatment compliance history based on unreliable evidence.

The case is inapplicable when there is contradictory expert testimony regarding treatment responsiveness, when a qualified mental health expert's opinion lacks credibility or is based on invalid premises, when there is substantial evidence supporting findings of treatment noncompliance, or when the defendant has been properly diagnosed and treated but still committed offenses.

The case leaves open whether prosecution must present expert testimony to rebut a defense mental health expert's dangerousness assessment, the scope of trial court discretion when multiple qualified experts disagree on treatment responsiveness, and the specific circumstances that would justify exercising residual discretion to deny diversion to an otherwise eligible and suitable defendant.