Legal Question in Elder Law in California

Unless and until your mother is officially incompetent, or he does something illegal, there is nothing you can do to remove him from your mother's home. If and when your mother is incompetent, then you would need to file immediately for conservatorship over the person and estate of your mother. At that point you would have full legal authority to do whatever is necessary and appropriate for your mother, her care, and her finances. Think a power of attorney on steroids (subject to court supervision and reporting requirements of course).

I agree with Mr. McCormick. I would also recommend that you speak to your mother's physican about your concerns as to her capacity. You will need to have the doctor evaluate your mother's mental capacity in order to move forward. Alzheimer's is a progressive desease, as you know, so sooner or later your mother will need you and/or your sister to handle her affairs for her.

Based on your post, I am assuming that your mother does not have a Power of Attorney or Advanced Health Directive in place. So, as Mr. McCormick has said, you will need to obtain a Conservatorship over your mother in order to manage her finances and her care.

I'm not sure what your relationship with your mother's boyfriend was before you moved in, but from your description of his behavior, it appears that he could be suffering from dementia himself. It could also be that he does not understand your mother's disease. Whatever his reasons and depending on the type of Conservatorship established, if either you or your sister (or both) are appointed Conservator, then you/she can make decsions in your mother's best interest including health, well being etc.