Here is the link to the ATF web site,
http://www.atf.gov/firearms/faq/unli...n-restrictions
Q: Are there certain persons who cannot legally receive or possess firearms and/or ammunition?
Yes, a person who —
1.Has been convicted in any court of a crime punishable by imprisonment for a term exceeding 1 year;
2.Is a fugitive from justice;
3.Is an unlawful user of or addicted to any controlled substance;
4.Has been adjudicated as a mental defective or has been committed to a mental institution;
5.Is an alien illegally or unlawfully in the United States or an alien admitted to the United States under a nonimmigrant visa;
6.Has been discharged from the Armed Forces under dishonorable conditions;
7.Having been a citizen of the United States, has renounced his or her citizenship;
8.Is subject to a court order that restrains the person from harassing, stalking, or threatening an intimate partner or child of such intimate partner; or
9.Has been convicted of a misdemeanor crime of domestic violence
10.Cannot lawfully receive, possess, ship, or transport a firearm.
A person who is under indictment or information for a crime punishable by imprisonment for a term exceeding 1 year cannot lawfully receive a firearm.
Such person may continue to lawfully possess firearms obtained prior to the indictment or information.
[18 U.S.C. 922(g) and (n), 27 CFR 478.32]