1. An unavoidable mistake regarding a fact constituting the criminal offense excludes criminal liability. If the mistake, considering the circumstances of the act and the personal circumstances of the perpetrator, was avoidable, the offense shall be punished, where applicable, as negligent.
2. A mistake regarding a fact that qualifies the offense or an aggravating circumstance shall preclude its consideration.
3. An unavoidable mistake regarding the unlawfulness of the act constituting the criminal offense excludes criminal liability. If the mistake was avoidable, the penalty shall be reduced by one or two degrees.