The power to create or change a legal document such as a will, advance directive or power of attorney comes from the person whose property or medical care will be
There is a legal requirement, however, that the person for whom such documents are made must be "of sound mind."
This mental competency requirement isn't too onerous to meet, but can be elusive to some people suffering from dementia. Generally, a person must be able to understand what the document is and does -- and must also be able to understand that he or she is making one. In the case of a will, the maker must be able to remember and understand who the beneficiaries are and what property they will get.
The capacity requirement is measured at the time the document is made or changed -- and that can be a tad tricky. Some people with dementia or Alzheimer's, for example, intermittently have the mental capacity that is legally required.
If you wish to contest the legality of a change in a legal document -- and it sounds as if you do -- then you must be able to show that the person actually lacked the required capacity when the document was changed, and that the document was written differently than it would have been if the person had the required mental capacity.
Another reality for you to investigate: If the documents were written or changed by a lawyer, it is also likely they were witnessed or notarized as legally required. One of the purposes of having a witness or notary on the spot when a legal document is signed is so that person can eyeball the person making it -- and later attest to his or her capacity if need be. If the documents weren't properly attested in this way, or witnessed by someone who couldn't verify the maker's legal capacity, that can sometimes render the documents invalid.
affected by it. Caregivers need not be consulted first.