Be honest, do you think it'd be interesting premise writing a story/book from a "victim's" point of view? It's about a serial killer killing women and having specific fixation and type, and by chance the killer moves next door to her and starts stalking/obsessing over her over the course of the book.
It'd be something like YA with the girl starting college and slowly escalate and reveal things as the book goes on. Not entirely dark/horror theme, but more like like a slow-burn plus some romance, bit of a cozy and slice of life kinda type in there too.
It'd be similar to the main character from the movie Run (2020) in terms of killer's intentions.