((a)) Any person who—

((1)) knowingly transports or ships using any means or facility of interstate or foreign commerce or in or affecting interstate or foreign commerce by any means including by computer or mails, any visual depiction, if—

((A)) the producing of such visual depiction involves the use of a minor engaging in sexually explicit conduct; and

((B)) such visual depiction is of such conduct;

((2)) knowingly receives, or distributes, any visual depiction using any means or facility of interstate or foreign commerce or that has been mailed, or has been shipped or transported in or affecting interstate or foreign commerce, or which contains materials which have been mailed or so shipped or transported, by any means including by computer, or knowingly reproduces any visual depiction for distribution using any means or facility of interstate or foreign commerce or in or affecting interstate or foreign commerce or through the mails, if—

((A)) the producing of such visual depiction involves the use of a minor engaging in sexually explicit conduct; and

((B)) such visual depiction is of such conduct;

((3)) either—

((A)) in the special maritime and territorial jurisdiction of the United States, or on any land or building owned by, leased to, or otherwise used by or under the control of the Government of the United States, or in the Indian country as defined in , knowingly sells or possesses with intent to sell any visual depiction; or

((B)) knowingly sells or possesses with intent to sell any visual depiction that has been mailed, shipped, or transported using any means or facility of interstate or foreign commerce, or has been shipped or transported in or affecting interstate or foreign commerce, or which was produced using materials which have been mailed or so shipped or transported using any means or facility of interstate or foreign commerce, including by computer, if—

((i)) the producing of such visual depiction involves the use of a minor engaging in sexually explicit conduct; and

((ii)) such visual depiction is of such conduct; or

((4)) either—

((A)) in the special maritime and territorial jurisdiction of the United States, or on any land or building owned by, leased to, or otherwise used by or under the control of the Government of the United States, or in the Indian country as defined in , knowingly possesses, or knowingly accesses with intent to view, 1 or more books, magazines, periodicals, films, video tapes, or other matter which contain any visual depiction; or

((B)) knowingly possesses, or knowingly accesses with intent to view, 1 or more books, magazines, periodicals, films, video tapes, or other matter which contain any visual depiction that has been mailed, or has been shipped or transported using any means or facility of interstate or foreign commerce or in or affecting interstate or foreign commerce, or which was produced using materials which have been mailed or so shipped or transported, by any means including by computer, if—

((i)) the producing of such visual depiction involves the use of a minor engaging in sexually explicit conduct; and

((ii)) such visual depiction is of such conduct;

((b))

((1)) Whoever violates, or attempts or conspires to violate, paragraph (1), (2), or (3) of subsection (a) shall be fined under this title and imprisoned not less than 5 years and not more than 20 years, but if such person has a prior conviction under this chapter, section 1591, chapter 71, chapter 109A, or chapter 117, or under the Uniform Code of Military Justice or the laws of any State relating to aggravated sexual abuse, sexual abuse, or abusive sexual conduct involving a minor or ward, or the production, possession, receipt, mailing, sale, distribution, shipment, or transportation of child pornography, or sex trafficking of children, such person shall be fined under this title and imprisoned for not less than 15 years nor more than 40 years.

((2)) Whoever violates, or attempts or conspires to violate, paragraph (4) of subsection (a) shall be fined under this title or imprisoned not more than 10 years, or both, but if any visual depiction involved in the offense involved a prepubescent minor or a minor who had not attained 12 years of age, such person shall be fined under this title and imprisoned for not more than 20 years, or if such person has a prior conviction under this chapter, chapter 71, chapter 109A, or chapter 117, or under the Uniform Code of Military Justice or the laws of any State relating to aggravated sexual abuse, sexual abuse, or abusive sexual conduct involving a minor or ward, or the production, possession, receipt, mailing, sale, distribution, shipment, or transportation of child pornography, such person shall be fined under this title and imprisoned for not less than 10 years nor more than 20 years.

((c)) ** .—** It shall be an affirmative defense to a charge of violating paragraph (4) of subsection (a) that the defendant—

((1)) possessed less than three matters containing any visual depiction proscribed by that paragraph; and

((2)) promptly and in good faith, and without retaining or allowing any person, other than a law enforcement agency, to access any visual depiction or copy thereof—

((A)) took reasonable steps to destroy each such visual depiction; or

((B)) reported the matter to a law enforcement agency and afforded that agency access to each such visual depiction.