Delaware Code
Chapter 3. PROVING AND DISPROVING CRIMINAL GUILT
§ 305. Exemption from criminal liability; affirmative defense to be proved by defendant.

When this Criminal Code or another statute specifically exempts a person or activity from the scope of its application and the defendant contends that the defendant is legally entitled to be exempted thereby, the burden is on the defendant to prove, as an affirmative defense, facts necessary to bring the defendant within the exemption.