Few facts you should note, make them clear, or get the details from bank. If you have deathe certicifate, 1st st check the date of with drawles of the cash. Next if possible establish the time of death, from the locals, try to make a proof, with nearbys etc make an affidavit about the time , date of death to the court. Mean time try to get the info from bank -when exactly it was with drawn fro the ATM. this wil prove who is correct. , as banks will even have the viedeo of the ATM with drawles.
With these details you can strengthen your case. Mean time you file a seperate case , of fraud .
Tell the court you will submit all the details .