A family member has taken all our aunt's money. We have proof. What can we do to get it back for her?

You may need to hire an attorney. I found that the police (even though they have a special unit to deal with this) and social services completely useless. Sorry to discourage you but I found no way to assist my aunt. However, my aunt was not willing to say anything negative about the person who had taken advantage of her.

Funny how the aunt hid 70 K around the house. This is what happens to people who don't use banks. Adults are allowed to make stupid decisions about how to keep their money. The clean out of the bank account is another thing entirely. If the person's name was also on the account, like Jane or Jack, they have every right to clear it out. If it's a valid theft, you immediately call the police.

Call the police immediately or better yet, go to the station and file a complaint and take all your proof with you. Make sure you make copies of all documents you have because they will want to keep some or all of it and you need a complete set of any and all papers. File for an injunction against the person who took the $70,000 and have the judge ask for an accounting of every penny spent that didn't belong to them. Sue them for anything they stole if necessary. You need to do something quickly before they go thru all the money.

24 linear inches of 1 inch rebar . that'll invert a knee cap like nothing else on earth .
strangely enough , i just brought 3 ea 8 ft sections home today . wanna buy some ?

The police. And look to see if there is a local Legal Services for the Elderly in your area. I think a pissed off legal elder advocate might be exactly what you need.

Contract the police since you have proof of these thefts.