Deceased fathers sister drained his account while he was incapacitated and dying in a hospital.

Location: Indiana

She was added as a joint owner with survivorship at an unknown time. She contributed not a single penny to the account and never used it.

While my father was dying in another state fully incapacitated, my sister flew out to be with him and my aunt also did at some point. When she seen the state he was in she left her dying brother and her niece to catch a flight back to their home state and drain his account. Over 80 thousand dollars. He died the next day.

While I understand survivorship rights that this money would have went to her after he passed what my concern is he was still alive and did not or could not authorize this. This account or money was never treated as hers until the day before his death.

He has 3 children. Myself and my 2 older sisters and he had no will. We’re his legal heirs and have been handling everything.

What can be done about this.