This man lies all the time about how much money he has and about cars, houses, etc. I found out he lives with his mum and is a conman who has been to jail twice for fraud. I have shown my mum the evidence and got the police involved, they said their hands are tied because my mum won't talk about it. He has been telling her she has dementia so every time I say something he turns to my mum and tells her she must have forgot. He has used all her money, but I am very concerned he is after the house now. This is not as simple as it seems like my mum seems to love him, she cannot see past him. Now my mum is not very well from an operation, and he has moved in upstairs to look after her.
You may have to "Call Ray" on your mum's boyfriend, if you get my meaning. Threaten the SOB in plain English, put the fear of Jesus into him while he's sleeping in your mum's upstairs room one night, since the police don't seem to be of much help. Do it on the QT, too, so mum isn't furious with you for running her beloved b/f out of town.
Best of luck
You say in her profile that she does have dementia.
If you are POA or another family member is then that person needs to step in and place her in Memory Care.
If no one is POA and she does have dementia she can not appoint anyone now so you or another family member need to become her Guardian BEFORE he gets the idea to become her Guardian.
Does your mom have dementia or is he just gaslighting her?
I have to tell you, though, that if the police say they can't make any progress with this because your mother won't co-operate then it isn't likely that Social Services will be any more optimistic.
When did she have the operation, who organized her discharge home from hospital, and where were you when this was happening? - it's a pity, because this was possibly a missed opportunity to intervene. Still, if it was a recent event, you might be able to do something with it. But does the boyfriend in fact take pretty good care of her?