Question about power of attorney

My husband and I have power of attorney for my father in law. He is 64 and
married a 28 y/o woman. She has had him arrested for domestic violence
several times. False charges according to my father in law. We were not
there to witness. As a result he is not allowed at his home. We have been
told by a third party that his wife has forged the title of his RV to pay of
a debt. She has also forged checks with his name to herself. One was for
400.00 and was paid. One was 400.00 and not paid due to ISF. My FIL is
laughing this off. Are my husband and myself in a position to file charges
against his wife since we have POA? They have only been married for 3 months.