Really, my library is quite brilliant to think of this. (OK, I know a library can't think, but you know what I mean.)
I have signed up and look forward to this overview of murder mystery fiction (and am hoping for an extensive reading list) taught by the provost of the community and technical college here. According to the LFPL website, the instructor has multiple degrees in English and I hope at least one degree in Mystery.
More to follow after I see what this 'body in the library' has to reveal.