my dad had a will but some one within our family had him sign a quit claim deed that we think was forged also my dad had dementia

Dear Michigan, You do not state whether your father is alive or deceased.  I'm going to assume from the read of your question that your father is alive.  I practice in Illinois, so please consult an attorney in your state to ensure I'm pointing you in the right direction.  There is probably a Department on Aging in your state which covers the financial exploitation of elders and elder abuse.  The matter you describe seems to fall right under this category.  Contact that department to file a report/complaint and they will likely have you file a criminal complaint with the State's Attorney General's Office and the AG's will investigate and get your family on the road to hopefully recovering your dad's assets and prosecuting that family member for whom I'm thinking of several names to call, but none of which would be appropriate.  Best wishes with everything.