It shall be unlawful for any person to knowingly sell, offer to sell, deliver, lease, rent, barter, exchange or transport for sale into this State any pistol to:

1. (a) Any person who has been convicted of a crime of violence in any court of the United States, the several states, commonwealths, territories, possessions or the District of Columbia or who is a fugitive from justice or a habitual drunkard or a drug addict or who has been adjudicated mentally incompetent.
2. (b) Any person who is a member of a subversive organization.
3. (c) Any person under the age of twenty-one, but this shall not apply to the issue of pistols to members of Armed Forces of the United States, active or reserve, National Guard, State Militia or R. O. T. C., when on duty or training or the temporary loan of pistols for instructions under the immediate supervision of a parent or adult instructor.
4. (d) Any person who by order of a circuit judge or county court judge of this State has been adjudged unfit to carry or possess a pistol, such adjudication to be made upon application by any police officer, or by any prosecuting officer of this State, or sua sponte, by the court, but any person who shall be the subject of such an application shall be entitled to reasonable notice and a proper hearing prior to any such adjudication.
5. (e) It shall be unlawful for any person covered in (a), (b), (c) or (d) of this section to possess or acquire pistols within this State.
6. (f) No person shall knowingly buy, sell, transport, pawn, receive or possess any stolen pistol or one from which the original serial number has been removed or obliterated.