Greg Deis has rejoined Mayer Brown in Chicago as a partner in the litigation and dispute resolution practice and the white collar defense and compliance group. Previously, he was an assistant US attorney in the criminal division of the US Attorney's Office for the Northern District of Illinois, which he joined in 2007 after four years as an associate at Mayer Brown. Deis was assigned to the public corruption section where he prosecuted numerous public officials and law enforcement officers for fraud, bribery, extortion and tax offenses.   Deis has served as an adjunct professor in criminal procedure and trial advocacy at DePaul University College of Law. He received his law degree from the University of Illinois College of Law.