"I had cared for an elderly woman with no family, who came to us when her husband died. She didn't often speak, but when she did, it was usually just words that made no sense together. I felt so bad for her because ever since she had arrived, so many of the residents in her area that she seemed to enjoy spending time with had passed in a short time span. She put up a picture of each of them next to her pictures of her husband and several others, who were probably family, to remember them. I had always felt sorry for her and showed her extra attention, so we became close. It just seemed so unfair that she had such luck and kept losing people that she cared about.
One day she looked at me and said plain as day, 'Sweetie, I think I'm done now,' and handed me a picture. It was a picture of me and I smiled, because it touched my heart that I was that important to her. She passed nearly a week later and I cried for days, it hit me really hard. She knew it was the end for her and she said goodbye as best she could.
A little less than two years later I was talking with a colleague and she came up in conversation. My colleague referred to her as 'that crazy witch', which seemed very out of character for her, and it shocked and offended me deeply. I expressed this to her, not so nicely, and she looked at me with this shocked look and said, 'Oh dear, do you not know?' and then explained something to me that I hadn't known.
As it turned out, it came out sometime after she had passed that she had killed her husband by poisoning him, and that there was an investigation because it appeared that she had a ritual of befriending someone, obtaining a picture of them, and hiding the picture until she could kill them (usually by poisoning). Then displaying the picture as a sort of trophy. It was suspected that this may have been the reason for the spike in mortality rate during her stay and the considerable number of photos in her 'collection'. The last I heard, the old 'family' photos weren't any relation to her and the police were trying to ID the individuals and compare them to several cold cases."