When it becomes necessary under this chapter to determine whether a minor participated in a sexual performance, the trier of fact may base its determination on personal inspection of the minor, inspection of a photograph or motion picture of the sexual performance, testimony by a witness to the sexual performance as to the age of the minor based upon the minor's appearance, expert testimony based upon the appearance of the minor in the sexual performance, or any other method authorized by law or by rule.
N.D.C.C. § 12.1-27.2-06