Seems to me, nowadays, serial killer books/TV programmes are like "celebrity", "reality", and "talent" TV shows/articles................
The first few were a decent idea, then they got boring, then they got appalling................
Books do at least have the saving grace of the infinite imagination - thus more likelihood of either a new wrinkle, or brilliant execution, (oops,

not) - well, you know what I mean.
[ If you don't, you've read too many serial killer books.]