2. a. A parent, guardian, or other person with legal custody of a child who knew or should have known of the disappearance of a child for which that parent, guardian, or other person is responsible who fails to report the missing child to the appropriate law enforcement agency within 24 hours shall be guilty of a crime of the fourth degree.
b. For the purposes of this section, a "missing child" means a person 13 years of age or younger whose whereabouts are not currently known.