Competency Is a Prerequisite to a § 16-8-107(3)(b) Mental-Condition Examination

I. Introduction

In People v. Day, 585 P.3d 857, 2026 CO 16, the Colorado Supreme Court addressed the procedural gateway for a defendant who does not plead not guilty by reason of insanity (“NGRI”) but seeks to present expert testimony “concerning the defendant’s mental condition” under section 16-8-107(3)(b). Maria Laida Day (“Day”) was charged with second degree murder and related offenses after she struck her boyfriend with her car and he died. Day maintained the death was accidental, making her culpable mental state—especially whether she acted “knowingly”—a central trial issue.

Day provided statutory notice of intent to introduce mental-condition evidence and sought to call a psychiatric expert, but no state-sponsored mental-condition examination was ever completed. The trial court excluded the defense expert and Day was convicted. A division of the court of appeals reversed in People v. Day, 2023 COA 115, and the Supreme Court affirmed the reversal on different grounds, announcing a clarifying rule at the intersection of competency doctrine and the statutory examination requirement.

II. Summary of the Opinion

The Court held that a defendant must be competent before undergoing a mental-condition examination ordered as a prerequisite to admitting expert mental-condition testimony under section 16-8-107(3)(b). Because a mental-condition examination requires the defendant’s meaningful personal participation, an examination attempted while the defendant is incompetent cannot serve the statute’s purpose, and the defendant cannot be penalized for “noncooperation” occurring during incompetency.

Applying that principle, the Court concluded the trial court abused its discretion by excluding all expert mental-condition evidence “on this basis alone” (i.e., Day’s failure to cooperate), where the relevant lack of cooperation occurred when Day was incompetent and the ordered examination was never completed while she was competent. The Court also agreed that the trial court’s exclusion was overbroad under People v. Moore, 2021 CO 26 because the trial court failed to separate evidence probative of “insanity” (inadmissible without an NGRI plea) from other mental-condition evidence that may be admissible for non-insanity purposes.

The Supreme Court affirmed the court of appeals’ reversal and remanded for a new trial on counts where culpability was at issue, leaving to the trial court on remand the remaining evidentiary questions—including Colorado Rule of Evidence 403 (“CRE 403”)— after a proper examination occurs.

III. Analysis

A. Precedents Cited

1. The statutory “insanity screen” and parsing requirement: People v. Moore, 2021 CO 26

People v. Moore, 2021 CO 26, supplies the controlling framework for deciding whether mental-condition testimony is inadmissible “evidence relevant to the issue of insanity” under section 16-8-107(3)(a) when no NGRI plea is entered. Moore instructs trial courts to determine whether the proffered testimony, “in whole or in part,” is probative of what the legislature has defined as insanity—i.e., whether it tends to show a “mental disease or defect” as defined in section 16-8-102(7) (“severely abnormal mental conditions that grossly and demonstrably impair a person’s perception or understanding of reality”).

In Day, the Supreme Court relied on Moore to fault the trial court for rejecting all of the expert’s proposed testimony rather than “distinguish what is probative of insanity under this exacting definition from what is not.” This reinforces Moore’s practical demand: courts must engage in granular parsing of expert opinions, admitting non-insanity mental-condition evidence (if otherwise admissible) while excluding the subset that crosses into statutory insanity.

2. Competency halts proceedings and limits what may occur: People v. Zapotocky and Jones v. Dist. Ct.

The Court’s new holding is anchored in competency doctrine. It cited People v. Zapotocky, 869 P.2d 1234 (Colo. 1994), for the rule that when there is reason to believe a defendant is incompetent, the court must suspend proceedings until competency is determined. It cited Jones v. Dist. Ct., 617 P.2d 803 (Colo. 1980), for the principle that the prohibition against prosecuting an incompetent defendant persists throughout the case lifecycle.

These cases, coupled with section 16-8.5-102(1) (allowing only matters “susceptible of fair determination” without the defendant’s personal participation), supplied the doctrinal bridge to the Court’s key move: a mental-condition examination under section 16-8-107(3)(b) requires personal participation; therefore, it should not proceed while the defendant is incompetent.

3. Standards of review and harmless-error doctrine: People v. West, People v. Kent, Hagos v. People, and People v. Johnson

The Court reiterated the abuse-of-discretion standard for evidentiary rulings through People v. West, 2025 CO 61 (quoting People v. Kent, 2020 CO 85): a ruling is an abuse if “manifestly arbitrary, unreasonable, or unfair,” or based on legal error. It applied constitutional harmless-error review because exclusion implicated Day’s ability to present a complete defense, relying on Hagos v. People, 2012 CO 63 and People v. Johnson, 2021 CO 35. This mattered because the prosecution relied heavily on Day’s post-event demeanor, and the excluded expert evidence was designed to rebut the inference that demeanor proved a knowing mental state.

4. Statutory interpretation and retroactivity on appeal: People v. Griego, People v. Ray, and People v. Owens

Statutory interpretation principles came from People v. Griego, 2018 CO 5 (plain-language approach). The Court also cited People v. Ray, 2025 CO 42M (quoting People v. Owens, 2024 CO 10) for the principle that appellate courts generally apply the law in effect at the time of appeal—explaining why Moore’s parsing framework applied even though the trial court did not have Moore at the time of its ruling.

5. CRE 403 requires attention to evidentiary purpose: People v. Cooper

The Court clarified that Moore’s statutory “insanity” analysis is not the same as CRE 403 balancing. Once evidence survives the statutory screen (i.e., is not probative of insanity), CRE 403 still permits exclusion if probative value is substantially outweighed by unfair prejudice, confusion, or misleading the jury. Citing People v. Cooper, 2021 CO 69, the Court emphasized that CRE 403 balancing must be “mindful of the purposes for which the testimony is offered.” This directly corrected the court of appeals’ suggestion that admissibility is measured only by “relatedness to insanity, not its proposed purpose.”

6. Non-“all or nothing” view of insanity evidence: People v. Vanrees

The Court invoked People v. Vanrees, 125 P.3d 403 (Colo. 2005), to reaffirm that Colorado’s statutory insanity framework does not create an “all or nothing” regime. Evidence relevant to disputed mens rea may be admissible even without an NGRI plea, so long as it does not tend to prove statutory insanity and complies with procedural prerequisites and the rules of evidence.

7. The dissent’s burden-of-proof authorities

The dissent—emphasizing a bright-line statutory bar—cited interpretive and evidentiary burden principles from Town of Minturn v. Tucker, Oakwood Holdings, LLC v. Mortg. Invs. Enters. LLC, and Dep't of Revenue v. Agilent Techs., Inc. (apply clear statutory text as written), and cases allocating admission burdens to the proponent of evidence: People v. Harris, People v. Vanderpauye, People v. Montoya, and People v. Sutherland.

B. Legal Reasoning

1. The Court’s core holding: competency is a prerequisite to the examination

Section 16-8-107(3)(b) permits expert mental-condition evidence absent an NGRI plea only if the defendant (1) gives notice and (2) “undergo[es] a court-ordered examination” under section 16-8-106. Under section 16-8-106(2)(c), noncooperation can result in preclusion of defense expert testimony.

The Court reasoned that “cooperate” means working with the evaluator and complying with the court order. But it then confronted the mismatch between that duty and incompetency: an incompetent defendant, by statutory definition (section 16-8.5-101(12)), lacks the present ability rationally to understand proceedings or assist counsel. Because a mental-condition examination requires personal participation and comprehension, conducting it while the defendant is incompetent undermines its validity and fairness. Therefore, the examination “shouldn’t proceed until the defendant is competent to proceed,” and any “noncooperation” during incompetency cannot justify precluding the defense expert. The Court characterized such an attempted examination, and the defendant’s cooperation (or lack thereof), as a “nullity.”

2. Why § 16-8.5-105(2) did not control—and why that did not matter

The court of appeals relied on section 16-8.5-105(2), which limits use of noncooperation in competency proceedings if the lack of cooperation results from a mental disability. The Supreme Court agreed with the result (Day should not be faulted), but clarified that this provision governs admissibility at competency/restoration hearings, not the later trial admissibility question for mental-condition testimony. The Court instead grounded its rule in the broader competency suspension principle in section 16-8.5-102(1) and cases like People v. Zapotocky.

3. The trial court’s error: using incompetency-based noncooperation to satisfy a statutory gatekeeping failure

The trial court excluded the expert in part because no mental-condition exam was completed and attributed that to Day’s noncooperation. The Supreme Court held this was an abuse of discretion because the relevant “noncooperation” occurred when Day was incompetent and because the trial court should not have treated that episode as disqualifying. Further, the Court stressed the practical reality that the defense repeatedly sought the exam and the court repeatedly ordered it; the system failed to complete it while Day was competent.

4. Moore parsing and the two-stage admissibility inquiry (statute first, evidence rules second)

The Court reaffirmed a two-stage inquiry:

• Statutory screen (Moore / § 16-8-107): exclude any portion of testimony probative of statutory insanity (i.e., tending to show a “mental disease or defect” under § 16-8-102(7)) absent an NGRI plea.
• Evidentiary screen (e.g., CRE 403): for what remains, apply ordinary rules of evidence, including balancing that depends on the purpose for which the testimony is offered.

The Court agreed that the trial court “swept too broadly” by excluding everything, and it corrected the court of appeals’ implication that evidence purpose is irrelevant to CRE 403. Nonetheless, because the missing examination could affect CRE 403 balancing, the Court left that question for remand after a proper exam.

5. The dissent’s competing rule: bright-line exclusion absent a completed exam

The dissent would have affirmed the trial court on the ground that section 16-8-107(3)(b) creates a mandatory prerequisite: no examination, no expert mental-condition evidence—“regardless of the reason.” It also criticized the majority for effectively shifting the burden of ensuring completion of the exam from the defense (as proponent) to the trial court, warning that trial judges must be able to rely on party notification in complex, long-running cases.

The majority did not deny the statutory prerequisite; rather, it held that the system cannot treat an incompetency-tainted attempt as a basis to preclude evidence and that courts should not allow the statutory prerequisite to be defeated by attempting or insisting on an examination during incompetency. Practically, the majority’s approach frames competency as an implicit condition precedent to a valid § 16-8-107(3)(b) examination.

C. Impact

1. Operational rule for trial courts

• No § 16-8-107(3)(b) mental-condition examination while incompetent: courts should ensure competency first, because the defendant’s participation is essential and incompetency makes the process (and any “noncooperation”) meaningless for exclusion purposes.
• Noncooperation findings must be time-sensitive: a “noncooperation” rationale is vulnerable on appeal if it rests on periods of incompetency.
• Moore requires line-by-line admissibility decisions: courts should admit permissible portions and exclude only the insanity-probative subset, rather than treating mental illness evidence as categorically equivalent to an insanity defense.

2. Consequences for prosecution and defense strategy

• Defense: Day strengthens the argument that delays or failures in completing the state exam cannot automatically forfeit the right to present a mental-condition-based rebuttal to mens rea, particularly where incompetency prevented meaningful examination participation.
• Prosecution: prosecutors can still insist on the statutory safeguards (notice and exam), but must be prepared for courts to re-order and time examinations around competency restoration rather than using incompetency-era “noncooperation” as a preclusion lever.
• Both sides: CRE 403 remains a meaningful battleground after Moore’s statutory screen; parties should litigate limiting instructions, risk-of-confusion, and “mini-trial” concerns with careful attention to purpose and the remaining (non-insanity) content of expert opinions.

3. Systemic effects (CMHHIP/resource constraints)

The record reflected repeated delays and logistical problems in completing examinations. Day’s rule increases pressure to coordinate mental-condition examinations with competency determinations and restorations. Where resource constraints delay exams, Day suggests that courts should be cautious about converting institutional failure into forfeiture of a defense theory—especially when the defendant’s competency fluctuates.

IV. Complex Concepts Simplified

• NGRI (Not Guilty by Reason of Insanity): a special plea that puts “sanity” at issue. Without it, Colorado generally bars “evidence relevant to the issue of insanity” (§ 16-8-107(3)(a)).
• Mental-condition evidence vs. insanity evidence: under People v. Moore, 2021 CO 26, the question is not what the defendant calls it, but whether it tends to prove the statutory definition of insanity—i.e., a “mental disease or defect” under § 16-8-102(7). If it does, it is excluded absent an NGRI plea; if it does not, it may be admissible (subject to prerequisites and evidence rules).
• Competency to proceed: the defendant’s present ability to understand the proceedings and assist counsel (§ 16-8.5-101(12)). Competency is about the here and now, not the defendant’s mental state at the time of the alleged offense.
• Why competency matters to examinations: a mental-condition exam is interactive; if the defendant cannot rationally understand what is happening, the examination cannot fairly or reliably achieve its purpose.
• CRE 403 balancing: even relevant evidence can be excluded if it is likely to unfairly prejudice, confuse, or mislead the jury. After the statutory “insanity” screen, courts still perform CRE 403 balancing, and the purpose of the evidence matters (People v. Cooper, 2021 CO 69).
• Harmless beyond a reasonable doubt: when an error impairs the right to present a complete defense, reversal is required if there is a reasonable possibility the error contributed to the conviction (Hagos v. People, 2012 CO 63; People v. Johnson, 2021 CO 35).

V. Conclusion

People v. Day establishes a clear procedural safeguard: competency is a prerequisite to a valid mental-condition examination under section 16-8-107(3)(b). A defendant cannot be penalized for failing to “cooperate” with such an examination when incompetency makes meaningful participation impossible. The decision also reinforces People v. Moore, 2021 CO 26 by requiring courts to parse expert mental-condition opinions and exclude only those portions probative of statutory insanity absent an NGRI plea, while leaving admissible portions to ordinary evidentiary scrutiny (including purpose-sensitive CRE 403 balancing).

In the broader landscape of Colorado criminal practice, Day tightens the linkage between competency doctrine and statutory mental-condition procedures, reducing the risk that fluctuating competency and institutional delays will function as an inadvertent forfeiture of a defendant’s ability to rebut the prosecution’s mens rea theory with appropriately limited expert evidence.