R.I. Gen. Laws § 11-31-16: Affirmative defense.

In any prosecution arising under § 11-31-1 or §11-31-10, it shall be an affirmative defense that the defendant was a bona fide school, or public library, or was a person acting in accordance with library collection policies pursuant to chapter 9 of title 29 and in the course of employment as an employee or official of such an organization.