Changing a will?

An attorney presumes someone is of sound mind unless he or she sees proof to the contrary. There is no standard procedure for this. It is based entirely on the attorney's subjective opinion of the person's state of mind at the time, how the person appears to them in the moment. If they see nothing that conclusively indicates their client isn't of sound mind, then they proceed. If they do see something, then they simply recuse themselves. An attorney cannot be held financially liable or be charged with misconduct for executing a document for a person who in their opinion is mentally sound, even if it turns out the person wasn't.

If the signer of a will wasn't of sound mind, then it is on you to prove that. You have the burden of proof. It is not the attorney's burden to prove that the singer was of sound mind.

As for guardianship, guardianship most often doesn't extend to matters of inheritance or legal transference of property. Whomever was the guardian, unless the guardianship papers specifically give that right, hasn't any say in those matters. The fact that the person had a guardian has no bearing. The will expresses that person's will and will be followed unless someone contests it and can prove to a judge in probate court that the person was not of sound mind. If the probate judge agrees, then disposition of the estate reverts to the next prior will, if any, or in accordance with the probate judge's findings, if no prior will exists. Even if the judge finds that the person wasn't of sound mind, the judge may still follow the will if nothing in the will seems irregular or out of place, like leaving everything to a wife, even a new wife. Or the judge may choose to throw out all of the wills since it's extremely difficult to prove for someone who wasn't of sound mind when had been the last time they were, because when you prove someone wasn't of sound mind, then you have the burden to prove that the prior will was made while the person was of sound mind, because as soon as you prove the person wasn't of sound mind for the later will, their being of sound mind is no longer the assumption for the prior will. So if the judge throws out all of the wills, with no will at all, everything goes to the surviving spouse regardless of the duration of the marriage. So you are going to have an extremely uphill battle trying to disinherit a surviving spouse, because in probate, surviving children do not have standing over a surviving spouse.

Another problem you have is if there was no prenup. It's general knowledge that a spouse inherits when their spouse dies. So if you can't prove he wasn't of sound mind when he married her, then if there is no prenup that specifically excludes her from inheriting, then it is reasonable to assume that he did want her to inherit, which would mitigate any will that predated their marriage.

Anyway, successfully proving the person wasn't of sound mind and getting the will thrown out does not expose the attorney to any liability.

Yes, but why would it occur to them too?

People with "severe dementia" do not have the mental capacity to process that sort of information.

They may remember they have a will, though probably not, but the idea that time has changed is beyond their ability.

If you found an attorney who is willing to do this you can have them disbarred and can contest the new will in court.

The point was this. His attorney knows he is not of sound mind. How. He petition on behalf of his new wife for the medical records which showed brain cancer and dementia. This is what he used for guardianship. My sisters went to see the Attorney with my father the attorney refused to meet with him unless his new wife was present. This Attorney was his Attorney before he became her attorney. My father said i want to change my power of attorney . He said you wife wants you to see a dr first. So way a long time after this the attorney changes he will where she gets everything.. Is this representing my fathers best interest. Its clear to me he sold him out to her.