That is the firm of Jim Thompson, former repug gov and current 9/11 commission member.
By the way, Patrick Fitzgerald is NOT a Chicago Lawyer, nor, to the best of my knowledge has he been in private practice. He was an ass't. US Atty in NYC and worked mainly in terrorism (one of the lead prosecutors in the first WTC attack.)
He was recommended and approved for Chicago's US dist Atty head post just a couple of years ago. From all I have read about him, he is any perps worst nightmare, a bulldog who cares about the constitution and the truth and little else, no time for politics for this guy.
I hope my impression is correct.
On edit, here's his bio:
http://www.usdoj.gov/usao/iln/patrickjfizgerald.htmland some more info, private firm for 3 years in NYC after graduation:
http://fitzgerald.senate.gov/usattorney/patfitzgerald.htm