Hi everyone,
I have a complicated situation.
In 2009 I met a woman (Vietnamese national) online. Trusted on what she say, I applied a fiance visa for her. In May 2012 she arrived in the USA. Soon after her arrival, I found out she is a cheater, she has a long term lover in Vietnam. They set up a scheme to cheat some US citizen to get in to US. I immediately stop the intention to marry her. She terrorized me and my parents so horribly. She made up a a fake domestic violent to harass me, then she went to a temple, paid the monk in there for him to hold a fake ceremony and also sign a fake paper for her. One terrible thing she dared to do is she back-dated the fake marriage license to 7/31/2012 which is the day her visa expired, despite the real day was 8/18/2012 (and I have the evidence which is the check stub and bank statement because she bargained with me to pay the monk if I don't want to be harassed more).
She then used the fake and back-dated marriage license to apply for green card. So the question here is, is that green cared considered legal? And if not, how can I prove it? what is procedure to do it?

Thank you for reading.

Best.