<prompt> Human: Using a throwaway for anonymity purposes. Heres the full story:My elderly great uncle, 80 yrs old, who is not of sound mind added a personal friendcaretaker to his checking account last November. My uncle suffers from either early onset Alzheimers, or some form of dementia - which can be backed up by his many doctors. Soon after this change, the caretaker withdrew over 100k from the account and never told my uncle. Within the last week, my uncle received his bank statement and saw the missing money. As instructed by my father, he went to the bank to see what had happened. The bank manager explained what he saw in the system, just as I had explained. My uncle has no memory of the events that led to adding someone as a joint account holder.I understand the pitfalls associated with a joint account and that there are virtually no protections against something like this from happening. At some point in the past, my great uncle also recognized this, as he wouldnt allow any of his family members to be listed on the account. However, this is very clearly a case of someone with a disability who is being taken advantage of.What is the best course of action moving forward here? Any and all advice will be greatly appreciated. Thank you!EDITUPDATE: Thank you to everyone for your help! We ended up closing all bank accounts that we could - they are opening an investigation into what happened. We cancelled all credit cards that we could. We went to APS in his area and started the paperwork with them. They said we should be hearing back from them within the week. And my great uncle moved in with my parents and they are going to take care of him for the foreseeable future. Its going to be a long road to recovery, but we were able to mitigate any additional damage.  <response>: Sue for elder abuse, retain a lawyer, find out whowhere this person is. Get power of attorney from the uncle into someones name who you can trust so he cannot add people to his accounts. 