Hiya Keggs,
I am sorry to read about the problems your mum is facing right now and as everyone says, no one is required to live their life in fear of being assaulted, whether the other person has dementia or not.
There are a number of things I think you should keep in mind:
1. That your mum needs a place of safety in the house where there is a lock on the door and ideally a phone in there so she can call out for help. The last thing either your mum or your dad needs is for her to be injured. This would be my first priority in terms of immediate protection for your mum.
2. You should encourage the carers to report the aggression too. All these reports help to elevate your dad so that he gets the attention he needs. It also means that its not just your mum's word about what is happening but introduces independent witnesses too.
3. If your dad is aggressive then your mum MUST call the police. She can explain he has dementia but the police are the ones with the power to do something about this immediately. They are also required to send reports of any incidents to his GP and to Social Workers. They are used to dealing with situations like this so they can be your friends in getting something done.
4. Your mum sounds like she has done a sterling job over the years but she needs reassurance that it is the dementia that is causing the problems and that sometimes the disease needs more than an untrained person can deliver on their own at home. Tell her that even if your dad is sectioned under the mental health act, that it doesn't mean that he won't be able to come home again. It means that he will get whatever treatment they can give him so that his symptoms are manageable. They will sort out medication and will observe him for a while to make sure he is functioning ok on a day to day basis before releasing him. Even if their recommendation is that he should be in a care home, your mum needs to know that this is a medical decision and nothing to do with her failing as a wife or carer. The thing is that the sooner he gets the attention he needs the sooner things can get resolved. To continue struggling just means your mum is putting her own health at risk and then where would you all be?
5. Ultimately, there is nothing at all anywhere that requires your mum to be your dad's carer. She cannot be forced to do it. If she has reached the limits of her endurance then that is it. Your mum herself is AT RISK, a VULNERABLE ADULT, being placed in a DANGEROUS ENVIRONMENT that could be INJUROUS TO HER HEALTH AND WELL BEING. Your dad is AT RISK due to refusing assistance. He too is a VULNERABLE ADULT. He is in danger of causing bodily harm to others, including carers and anyone who tries to assist him. He is out of control.
Above is just my thoughts on the matter. You and your mum are doing everything you can to help your dad and you should be commended for that. I hope you get the resolution you are seeking and that your dad gets the help that he needs soon.
Fiona