D.C. Code § 22-3056
§ 22-3056. Affirmative defenses.
It shall be an affirmative defense to a violation of § 22-3052 , § 22-3053 , or § 22-3054 if the disclosure or publication of a sexual image is made in the public interest, including the reporting of unlawful conduct, the lawful and common practices of law enforcement, or legal proceedings.