USCIS Memo on Eligibility to SP as Intended Spouse – Bigamy Memo (August 21, 2002) [pdf]
The purpose of this memorandum is to inform Immigration and Naturalization Service officers in the field of the change in the law concerning the eligibility to self-petition as an intended spouse of an abusive United States citizen (USC) or lawful permanent resident (LPR). This change in the law protects battered immigrants who believed s/he
was married to a USC or LPR, but later discovered the marriage was not legitimate because of the bigamy of the USC or LPR.