Short story read in the early 2000s, a writer writing on a typewriter about the story unfolding and it ends with a killer coming up from behind him

[Trish]

I remember it being really short (maybe one or two pages) and I think it was by a Latin American author but that could be wrong. All I remember is that it's about a hunter or killer tracking someone who turns out to be the man who is typing the story on a typewriter and it ends with him approaching the writer from behind. Read in the early 2000s for a high school class, but I suspect it's a lot older.