Too little, too late. Rahm Emanuel is already entrenched, and far beyond the feeble power of the Chicago City Council to be held to account.
One former mayor of Chicago, Michael Bilandic, got blown out of the office of Mayor after the blizzard of 1979, but there was no particular effort to cover up an obvious murder in that incident. He was voted out of office, and went on to become Chief Justice of the Illinois Supreme Court before retiring.
I know I am not holding my breath for him to resign.