(a) Offense.--Unless the circumstances reasonably indicate that the child is in need of assistance, a person who lures or attempts to lure a child into a motor vehicle or structure without the consent, express or implied, of the child's parent or guardian commits an offense.

(a.1) Grading.--The following shall apply:

(a.2) Mistake as to age.--If an offense under subsection (a) involves a child under 13 years of age, it shall be no defense that the defendant did not know the age of the child or reasonably believed the child to be 13 years of age or older.

(b) Affirmative defense.--It shall be an affirmative defense to a prosecution under this section that the person lured or attempted to lure the child into the structure for a lawful purpose.

(c) Definitions.--As used in this section, the following words and phrases shall have the meanings given to them in this subsection:

“Child.” A person under 18 years of age.

“Motor vehicle.” Every self-propelled device in, upon or by which any person or property is or may be transported or drawn on a public highway.

“Structure.” A house, apartment building, shop, warehouse, barn, building, vessel, railroad car, cargo container, house car, trailer, trailer coach, camper, mine, floating home or other enclosed structure capable of holding a child, which is not open to the general public.