Chicago Hypothetical

So the British paper 'Guardian' published a piece stating that a place called 'Homan Square' is used for 'CIA like' incarceration, detention, and interrogation.  The CPD of course denies it all. 

Not that there'ld be any precedent of course, but let's use our imagination and pretend each and every one of the allegations is true about the place. 

There yet?  Good.

Now, who's been in charge of Chicago (and its police force) since time immemorial?