Stepfather bragged that when he got my mother's power of attorney when she had cancer that he used it to change her life insurance policies to pay him

Stepfather had no children. Had a friend write wills for him and our mother. Hers left assets to him and referred to a separate list of personal items bequeathed to each child. She named her children as beneficiaries of her several life insurance policies before marrying. She suspected she would die of a second round of cancer. She spoke of her lists of which child would get which personal item, collectible or piece of jewelry. Her will said the list would b valid even though not stored with the will since she wanted to keep adding to it over time. When sick, our stepfather got her power of attorney, put her in hospice, took her PoA to banks and life insurance companies and made himself the beneficiary of everything she had tried to leave for her daughters. She died and he claimed he didn't know where the "list" was, gave nothing to her children, bragged he'd changed all her bank account PoDs and life insurance policies to pay him, alone, married a childless widow and then died. Help!?