I agree with Attorney Farley. Furthermore, this matter appears to already be in the courts, where it sounds like it belongs. No one appears to have legal authority to do anything with your father or his belongings, at this point. You need to retain an attorney to assist you in getting conservatorship, because it seems pretty clear that your brother is going to fight you on this.
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Mr. Frederick is correct. It certainly sounds like someone needs to be appointed to look out for your father's interests. An attorney can help make sure it is done correctly. Your brother is not likely go to go jail but at least your father and his things can be protected.
You should get an Elder Abuse Restraining Order against your sibling, based solely on the unauthorized sale of your dad's property. (Obviously, you will need some type of proof and Declarations showing this). I would also maybe try to go Ex Parte before the Court, so that the Court can give you a quicker Temporary Conservatorship over your dad. Of course, if your dad does not want to file the Elder Abuse Restraining Order himself, and you yourself have no Court-ordered representative role over your dad, then the Restraining Order will be denied.
On a side note, you might want to apply for the Conservatorship ASAP and then you can continue the next Restraining Order hearing, and then attempt to consolidate both cases into one Case Number. I cannot guarantee that they will be consolidated, but it is worth trying at least. . .