My next door neighbour who had medium dementia died really quickly in a care home in the summer of 2020. He died quickly of pneumonia pretty much over a day. The care home wanted to write it down as covid even though he had had several tests which were all negative. He wasn't a fit person, but he had no specific illnesses that I know of except the dementia. I think it is likely that he was murdered, He was in his mid seventies. I was not expecting him to die.