What if a "scam artist" is operating as a POA?

You cannot get a copy of the POA. POA ends at death. Wills have to be probated in court, by a judge who demands solid documentation. You have no right to any claim, since you are not a relative and have nothing in writing. It does not matter where the notary works, their authority comes from the state. Sorry, but I think the scammer was the deceased who played you for a fool.

Your other posts shed some light on this. It is still somewhat confusing, though. This friend that you cared for has died. You say that she promised to compensate you in her will yet you also say you'd seen the will and she left everything to an animal organization. Why would you believe you would be compensated in the will when the will did not contain that provision? Even if you could prove fraud and produce a copy of the pre-fraud will, the money would go to the animal people, not to you.

It is a serious mistake to not be paid for caregiving services while the caregiving is going on (if you expect compensation). Accepting promises of being compensated in a will is, as you've discovered, very risky. Why didn't this wealthy woman pay you weekly or monthly?

Whether you had hard evidence of fraud or not, I don't see how you have a case for compensation from the estate. You might get your wish that someone goes to jail, but it seems unlikely to me that you will get money out of this situation. But I'm certainly no lawyer. Have you talked to one?

Also see Massage's answer on this thread:

https://www.agingcare.com/questions/too-late-for-caregiver-agreement-212073.htm?cpage=1

I suggested in that thread that Massage go to the police with her accusations. Massage, have you done this? What did the police advise/do?

Massage, apparently this has been a running issue since last April when you wrote https://www.agingcare.com/questions/can-you-bring-unpaid-caregiving-for-elderly-against-estate-198610.htm

Is this wealthy friend competent? What is her impairment? Does she realize that the POA has stolen from her? How is he keeping you away from her? That is beyond the authority of a POA.

A little more information would help.