A police officer executed a search warrant of defendant’s home and found four guns that defendant owned. Defendant had a prior felony conviction and was charged with possession of a weapon by a previous offender (POWPO). Before trial, defendant endorsed the affirmative defense of mistake of law. The court rejected the affirmative defense, found defendant guilty of the POWPO count, and sentenced him to 18 months of probation.

On appeal, defendant argued that he was entitled to the affirmative defense of mistake of law because the Colorado Bureau of Investigation (CBI) gave him permission to possess all the guns when he passed background checks before purchasing two of them at Walmart. A mistake of law defense arises from the mistaken belief that conduct does not, as a matter of law, constitute a criminal offense. It is not a defense unless the conduct is permitted by certain law, persons, or entities under specific circumstances. As the state point of contact for the national instant criminal background check system, the CBI is required to deny a background check if the transfer of a firearm would violate state law. But even if passing a background check could be construed as a “grant of permission,” the CBI doesn’t have the authority or duty to interpret, apply, or grant exemptions from the POWPO statute. Defendant presented no evidence of an administrative regulation, order, or grant of permission by anyone authorized or empowered to give such permission that would have permitted him to possess firearms. Nor did he present evidence of an official written interpretation of the POWPO statute by anyone empowered to make such an interpretation giving him permission to possess a firearm. Therefore, defendant was not entitled to have the fact finder consider the affirmative defense.

The judgment was affirmed.