(a) Any adult, being at least 2 years older than a minor, who commits a crime of violence against that minor may be punished by a fine of up to 1 1/2 times the maximum fine otherwise authorized for the offense and may be imprisoned for a term of up to 1 1/2 times the maximum term of imprisonment otherwise authorized for the offense, or both.
(b) It is an affirmative defense that the accused reasonably believed that the victim was not a minor at the time of the offense. This defense shall be established by a preponderance of the evidence.
(c) For the purposes of this section, the term:
(1) “Adult” means a person 18 years of age or older at the time of the offense.
(2) “Crime of violence” shall have the same meaning as provided in § 23-1331(4).
(3) “Minor” means a person under 18 years of age at the time of the offense.