*Social services will do absolutely everything they can to avoid placing anybody in residential care. They will say it's in the best interest of the client but really it's because the places do not exist because they cannot afford to pay for them. You have to be extremely rich to afford to pay for this privately (minimum £5,000 per month).
Sorry OP, this doesn't help you I am just frustrated by how often I read people on MN talk about 'putting' people in residential care. Even when it absolutely would be the best thing for everyone concerned it is incredibly hard to arrange this unless you have the agreement of the person concerned and you are super rich.*
ITA. IMO, some posters are being naive about residential care. First of all, the LA should do an assessment of NDN's capacity. If she still has capacity (and lots of people have anti-social behaviour with capacity), then they cannot just "put her in residential care", unless she agrees. Its in a contravention of her human rights, and right to a private and family life in her community. We are not living in the 19th century, when single pregnant women, inconvenient wives, etc could just be put in asylums.
If she does not have capacity, then they can put her in a residential care home if its in her best interests; but its not a magic wand that can cure challenging behaviour (unless it has a simple explanation like an UTI). People with challenging behaviour just carry on assaulting the residential care workers, rather than the community care workers.
DD has challenging behaviour and learning disabilities - she has been in the most specialist residential care; and is deemed to need 1:1 care. There are people in those homes who need 2:1, 3:1 or 4:1 care - because even the onsite teams of clinical psychologists, educational psychologists, consultant psychiatrists, mental health nurses, speech therapists, OTs, etc cannot cure the challenging behaviour.
Actually, DD's behaviour is better with us than residential care workers, because we understand her better than anybody else - however. as for swearing, we must have told her a million times in the last 8 years not to swear; and careworkers must have told her a million times not to swear; and its not made a blind bit of difference to DD. What sanctions do posters think work against an adult, with learning disabilities, who ignores what you say; does not care about money (which they don't really understand anyway), does not care about the judicial system (which is also meaningless to them) and does not understand star charts?
It is easier to get blood out of a stone, than get a LA to fund that kind of care. Actually, someone living in their own home is cheaper, because they may get housing benefit, ESA or a pension, and PIP, which go towards their living costs. Once in residential care, the LA has to pay all the costs of the residential care - which can be £250,000 or £350,000 pa upwards. The service user won't get housing benefit or PIP; once in residential care, although the LA can take all their pension or ESA and leave them about £26 per week for toiletries, clothes, etc - but that is a drop in the ocean against £250,000 pa!
By all means OP, raise safeguarding concerns, if you wish to protect DS; but don't think NDN's challenging behaviour is necessarily just down to unmet needs, which would all disappear in residential care.