A not-guilty-by-reason-of-insanity (NGI) plea asks whether you were legally insane when the charged act happened. If you also plead not guilty, the usual sequence is a guilt trial followed, if necessary, by a sanity trial; a defendant may waive separate phases and have the issues tried together. If you plead NGI without also pleading not guilty, California law treats that as admitting that you committed the charged offense. An NGI finding does not mean you simply walk out of court: the judge must address treatment placement and later release under separate rules. (Penal Code § 1016; § 1026)
Decide what each plea asks the court to decide
The combination of pleas is consequential. Separate phases are the statutory default, but a defendant can waive that separation after advice from counsel. Under the usual separate-phase procedure, with not guilty plus NGI, the first phase tests whether the prosecution has proved the charged crime. During that phase, the defendant is presumed sane for purposes of the trial. If the factfinder finds guilt, the sanity question is then tried before the same jury or, at the court’s discretion, a new jury. If the finding is sane, ordinary sentencing follows. If the finding is insane, the court turns to the placement and release rules described below. (Penal Code § 1026(a))
Before entering either plea, ask counsel to identify the exact counts, what you contest about the alleged acts, and which records speak to your condition at the time of each act. A diagnosis today does not by itself establish legal insanity then. Present competency is a different question: Penal Code section 1367 asks whether a person can now understand the proceedings and rationally assist counsel. Mental-health diversion is also a separate pretrial procedure with its own eligibility and suitability rules. (Penal Code § 1001.36)
What must be proved in the sanity phase?
The defendant bears the burden of proving legal insanity by a preponderance of the evidence: more likely than not. The relevant question is whether a mental disease or defect left the person unable to understand the nature and quality of the act or unable to understand that it was morally or legally wrong when it occurred. Although Penal Code section 25(b) prints “and” between the two incapacity descriptions, the California Supreme Court construed them as alternatives in People v. Skinner. The current CALCRIM No. 3450 states that test using “or.”
The standard is narrower than simply having mental illness. The court appoints two qualifying psychiatrists or psychologists, and may appoint a third, to examine the defendant and investigate mental status; either side may also present other expert evidence. Counsel can compare those reports with treatment records, observations close to the alleged act, and the account of what happened. (Penal Code § 1027) Section 29.8 also bars an NGI finding based solely on a listed personality, adjustment or seizure disorder, or addiction to or abuse of intoxicants. Recent intoxication by itself is not the same as legal insanity. (CALCRIM No. 3450)
What happens after an NGI finding?
The court orders a community program director or designee to evaluate placement and recommend whether the person should be an outpatient or committed to a state hospital or another approved treatment facility. The court may use a qualifying facility or outpatient route; it does not automatically order hospital confinement in every case. If it appears to the court that sanity has fully recovered, section 1026 instead directs remand to the sheriff while that issue is finally determined. Release from confinement or outpatient status requires the statutory court process, rather than following automatically from the NGI verdict. (Penal Code § 1026(a)–(b))
The commitment order must address a maximum term, but there is no single fixed NGI term for every charge. The calculation depends on the offense and, for a felony, the maximum imprisonment that could have been imposed and applicable credits. A qualifying felony commitment can be extended beyond that term only through a separate petition and hearing when the statutory mental-disorder and substantial-danger conditions are met; extension is not automatic. (Penal Code § 1026.5(a)–(b))
If you or a family member is considering an NGI plea, bring the charging papers, plea discussion, past and current treatment records, and any evaluations to counsel. The choice affects both the guilt contest and what can happen after a sanity finding. For the broader defense of a serious charge, see the Law Offices of David S. Chesley’s murder and homicide page. Call (800) 755-5174 to discuss the actual case and plea options.