People v. Mion.

2026 CO 5. No. 24SC2. Affirmative Defenses—Involuntary Intoxication—Statutory Interpretation.

January 26, 2026

Involuntary intoxication is an affirmative defense to all crimes, provided that the intoxication is not “self-induced.” CRS § 18-1-804(3). “Self-induced intoxication” occurs when a defendant “knowingly introduce[s]” substances that the defendant “knows or ought to know” cause intoxication. § 18-1-804(5). The supreme court held that, when a defendant contends that there are multiple intoxicants in a product that they consumed, a “substance” per § 18-1-804(5) is the entire product, not each “particular intoxicant” within the product. Interpreting “substance” as the entire product allows courts to consider a defendant’s reasonableness under the “ought to know” prong of the statute and thus effectuates the legislature’s intent.