My brother took control of everything when my father passed and no will

I have not been able to get any information from my eldest brother who seized my father's assets and distruuted some from what I hear he also placed the property my dad had into his name after my father's death. I don't believe he had the authority to do so since I am the executor of the estate now after going to court for it. My brother thinks I received that court title because I was awaiting to receive a payout on an insurance claim for theft of my property at my dad's home where I lived and about over. Year ago filed a claim to my father's home owners insurance. My brother had power of attorney because my dad was living in CA and my brother had been paying his bills remotely for him while he was away and I believe he ised that to gain access to his bank accounts and assets and property. I am confused as what to do now that I located the property dad recently purchased and only lived in a month prior to him dying in Oct of last year. There is someone living in the trailer and I called the property people for my county and was told my oldest brother put it into his name in December that's two months after my dad's death. There isn't a will and it isn't registered and if thier is any papers stating he is in sole control he has yet to produce them or even discuss that to the other siblings. I as executor do not know how I go about getting him to surrender the assets he took or inventory what he has left because my brother is unwilling to talk to any of us regarding this. What do people do when these types of circumstances arise? Any suggestions are greatly appreciated. Thank you