Where is the 2-7?

[keerawa]

So, after some research, I've discovered that Chicago does not actually HAVE a 27th police district.

I'm starting work on a fairly involved, case-based story, and I would really like to get some idea of where the station house is, and which neighborhood of Chicago they are responsible for. Is there any canon or widely accepted fanon that would indicate where in Chicago I could place it?

Are there any present or former residents of the Windy City that might be willing to answer the occasional random email for points of local color?

Thanks!