Great Aunt Dies And I Believe Her Friend Was Involved In Her Death

i need help. my great aunt died recently due to a fall, and i believe her neighbor/ friend got her drunk and on drugs to induce a fall.

my aunts friend has his hands all over; in her bank, code to the house, code to the safe, etc my aunt trusted him with every every detail of her life. She also has life insurance and because it was an "accident" i guess they got money from it as well because we havent seen any of that and dont really care about that. her bank account is completely empty. her safe was EMPTY. she had money and guns in it as well as legal papers. her friend claims they took all her money out to lie to the goverment and get income or i dont know im just hearing all of this.

long story short he is the power of attorney and yadada, he had his name on my aunts account and after she died we didnt get ANY papers. Nothing. that all went to her friend. Now that we got the paper a few weeks ago we went to the bank and my dad is the beneficiary of the bank account

should we persue legal help? or is it useless because theres very little proof of anything and his name was on my aunts bank account , so is there any way we can get the money back?

theres so much more to the story but its hard to mention everything.