The Supreme Court reviewed whether legislation prohibiting the sale, transfer, or possession of a “large-capacity magazine” violates the right to keep and bear arms protected under Colo. Const. art. II, § 13. Relying on its longstanding test under Robertson v. City & County of Denver, 874 P.2d 325 (Colo. 1994), for examining challenges brought under § 13, the Court concluded that the legislation is a reasonable exercise of the police power that has neither the purpose nor effect of nullifying the right to bear arms in self-defense. Accordingly, the Court affirmed the Court of Appeals’ judgment.

The Supreme Court held that it’s improper to argue that a defendant acted unreasonably in self-defense in failing to retreat from an encounter before using defensive force. Colorado’s longstanding no-duty-to-retreat rule permits non-aggressors to stand their ground when acting in self-defense. Here, the prosecution argued that defendant’s failure to retreat undermined the reasonableness of her belief that she needed to act in self-defense. Because such argument is improper, and because the trial court’s error in permitting that argument wasn’t harmless, the Court affirmed the Court of Appeals’ judgment on different grounds, reversed defendant’s judgment of conviction, and remanded the case for a new trial.