What's the Name of That Book??? discussion

I read a compilation of short stories by Stephen King and cant find it-this is the one i remember best: a serial killer kills women, in the end it turns out the killer is a lesbian woman that worked in a bookshop where the victims bought books. There was also one about a boy who was terrified of a creature coming out of his closet.
ETA: As i read this book in Spanish translation, it also might be that the short stories are different from English editions.

Maybe Night Shift? I'm not sure about the lesbian serial killer, but the other might be "The Boogeyman."

There's a serial killer and a closet monster in Night Shift, but the killer is a man. There's a lesbian villain in Full Dark, No Stars, but she's not the actual killer. She does work in a library, though.

I might be mixing up stories. Ill check Night Shift which seems to be the best match. Thank you.

Have you found it? It might be on this list of Stephen King's short stories:
https://www.goodreads.com/list/show/2...

There’s a serial killer in Just After Sunset. I don’t see anything about a boy with Monsters in his closet in that collection though.