My mother, aged 75, has advanced Alzheimer’s. This is heart-breaking enough – she is now at a stage where she has terrifying visions, and keeps asking me, her only son, where her son Mark is. But twice in the past five years we have been denied justice in cases where people were suspected of taking advantage of mum because of her vulnerable state.

Until last October, mum was able to live with a modicum of independence with the help of care from a local authority team. Support workers came to visit twice a day, helping her with everyday essentials such as cleaning, eating, and shopping, and mum developed a real rapport with the team. The care wasn’t cheap – indeed, by the end the monthly fees swallowed her teaching pension – but we judged it worth the cost in order for mum to retain some dignity.

Then I received a tearful phone call from the leader of the care team that had been looking after mum. It was suspected that one of mum’s carers, who she had come to trust implicitly, had been stealing from her. Other carers within the team had grown suspicious at a number of discrepancies with receipts. I was both shocked and angry; the fact that mum had absolutely no idea what was going on if anything made it worse.

When confronted, the carer in question resigned her post, and avoided questioning by police for many months. Initially police thought she had gone into hiding – then an officer called to sheepishly admit she had apparently been at home all along. At my insistence, the police went back to knock down her door, and she was finally questioned. Due to my holding Power of Attorney, I was questioned at length, provided a formal statement, and was asked to provide mum’s bank statements so police could check for suspicious activity. I now saw that many hundreds of pounds had been withdrawn from mum’s bank account for which there was no apparent explanation. Interestingly, these withdrawals stopped the day the suspect was confronted. Finally, the police now satisfied they had enough background, evidence was submitted to the CPS.

However, I have recently discovered that the CPS has thrown out the case. The fact it was the carer’s own employers who reported her to police – knowing this could risk reputational damage – counted for nothing. The suspect is free and won’t be charged; presumably they might even ask for their old job back (I did contact the local authority operations manager to find out if this is a possibility but they failed to respond). My only consolation is that due to her deteriorating condition mum is completely unaware of what happened. Following a series of scares, including falls, walkabouts and hallucinations, last October she was assessed as being unable to live independently and moved to a residential home in Halifax.

This was the second time we believe people have taken advantage of mum. Five years ago, when her condition was affecting her judgment and short-term memory but had not yet been formally diagnosed, as we drove through town, she pointed out a man who she said was ‘a nasty piece of work’ and kept pestering her for money – at one point, barging his way into her house. It turned out other local scumbags had been targeting her too. Locals who knew she was vulnerable told me they had seen her ‘marched’ to ATMs to withdraw cash, and her current account had several mysterious withdrawals.

When I contacted police on that occasion, they were deeply unhelpful, visiting mum without an appointment and questioning her at length without anyone else being present – despite the fact her memory was already failing, and she was incredibly distressed. They explained to me that they had phoned the man in question, and he had denied demanding money – which apparently was enough, as it was her word against his.

In both cases, it seems to me, mum was denied even the prospect of justice simply because she has Alzheimer’s. On both occasions, we were informed she was unreliable as a witness – and so despite the fact I could act on her behalf, the suspect avoided facing justice. Of course, it’s possible that in both cases there was a perfectly innocent explanation – but we will never know. (A CPS spokesperson said: ‘Where a complainant has a medical condition which means they struggle to recall information we would look at other admissible evidence to build the case. This can include financial records, the accounts of other victims or witnesses, and the forensic analysis of mobile phones and other digital devices. We will always prosecute cases that meet our legal test, however if there is insufficient evidence to provide a realistic prospect of conviction, we cannot proceed.’)

I now believe the CPS and police need to update their policies to take account for the fact that more and more of us are living with conditions like Alzheimer’s – and find a way to ensure that if they are thought to be victims, their stories will be investigated thoroughly.

Every couple of weeks I make the trip from London to Yorkshire to visit mum in a home. The anti-psychosis meds have taken away the most terrifying visions, and the anti-depressants generally keep her mood light, but seeing your outwardly healthy mother slowly revert to a childlike state makes each visit more harrowing. It’s bad enough seeing your loved one slipping away before your eyes, but even worse when you believe they are being preyed on by those who are supposed to care – and there’s nothing you can do about it.