Legal Question in Elder Law in California

You don't get a power of attorney from a notary. They just verify and certify that the person who purports to have signed the document is the person who signed the document. You can get a power of attorney from a reputable publisher, such as Nolo Press books, or from an attorney. The real question, however, is if it will be valid. The answer to that depends on your father in law's mental state. If his dementia is in the early stages and he is still fully capable of making decisions on his own behalf, he can execute a valid power of attorney. If he is already mentally unable to fully comprehend and make decisions on his behalf, then it is too late for a power of attorney; you would have to get a conservatorship (which is much like a power of attorney but can be extended to control over the person as well as their affairs, and is under court supervision). If you are still able to get a power of attorney, make sure it is a durable power. A regular power of attorney is precisely co-extensive with the power of the person who gives the authority to the attorney in fact. Therefore, when the grantor of the power becomes incapacitated, the power of attorney ends. A durable power of attorney survives the incapacity of the grantor of the power.