Legal Question in Wills and Trusts in California

if the signature is forged (and that can be proven) the document is not valid. Was it notarized? You can request a copy of the page in the the notary's book showing your dad's signature method of identification.

Yes your Dad would have had to sign the power of attorney unless it was signed for him at his direction which would have to be reflected on the document. However, challenging a POA which expired when your Dad died does not make sense. You need to consult with an attorney, who can review all the facts and the documents and give you specific legal advice.

Mr. White is correct. I was about to send you a P.S. that the power of attorney is no longer effective anyway since your dad has passed away.

You have gotten correct answers. If a person grants another person any form of POA, the person granting the power must sign the POA document. If they are of sound mind and for some reason cannot sign, there must be careful documentation of consent, including as Mr. White noted, stating that fact in the document. It sounds like you may have a serious case of elder financial abuse. You should talk to a lawyer directly as Mr. White suggests. I would also add, that you need to be sure of what jurisdiction is relevant. You posted your question to California lawyers while listing a Washington zip code. The state in which your father lived and died is the state that has jurisdiction.