She says people are trying to kill her and involved the police. A problem is her doctors say she is fine - no diagnosed dementia since she refused additional neuropsych eval. In private, around family, she is VERY unstable. In public she appears fine - more or less. She refused to do additional neuropsych eval. My father passed last year, I'm on only child, so I am looking for a solution. A problem is she refuses to be taken care of and insists on living alone.
If she has not been declared incompetent and will not cooperate with you, her concerned child, then the authorities are in charge.
The appearing normal in public is known as "showtiming" and many persons with early dementia can pull this off, at least for limited periods.
I really hate to say this, but you may have to wait until she brings some consequences upon herself. For example, she may call the police one time too many and they'll take action. I agres with BarbBrooklyn that it might be good to report her to APS, if only as a CYA for you. Unless your mother is obviously in need of help when they visit, they may not be able to do anything immediately.
My heart goes out to you. It is so hard to see a loved one on a self-destructive path.
https://www.agingcare.com/articles/hallucinations-delusions-and-paranoia-151513.htm
Your mother's behavior is not unusual and it may very well take a crisis to move things forward for the better - no one wants to medicate their parent especially when most drugs used carry black label warnings from the FDA but if she believes someone is out to kill her then she needs treatment
I hope you have POA for your mother both financial and health - if not try to consult an elder attorney or contact your county area agency on aging
Try to take stock of your mom's finances and start looking at nearby assisted living / memory care facilities
She will not be able to live alone much longer
Dementia is a long tiring journey
I worried to death and talked to every elder expert and case worker with the basic conclusion " you have to wait for something awful like hospitalization before anything can be done". For me, there have been several police visits and calls, APS, bank calls, utilities turned off, stroke...and she still gets returned to her home fortress. Nothing I can do and suspect similar for you.
Just document everything and report to APS and ask them to do well check.
I have POA provided 2 Drs sign off but they don't want to sign and mom refuses psych consult. APS wants me to go for guardianship but I have refused. We are all at stalemate until mom is hospitalized. Sad state but this is a broken system when you can't help a parent or elder when you know they need the help but legally their rights trump their well being -- at least until it gets dire.