(d) It shall be unlawful for any person to sell or otherwise dispose of any firearm or ammunition to any person knowing or having reasonable cause to believe that such person, including as a juvenile
(1) is under indictment for, or has been convicted in any court of, a crime punishable by imprisonment for a term exceeding one year
For those wondering.
EDIT: This is incorrect. It is 18 USC § 922 (n) as indicated by my reply to @Neato and thanks to them for pointing out my error.
theodewere