J. Gregory Deis

Mayer Brown

J. Gregory Deis is a partner and Co-Chair of the Firm’s White Collar Defense & Compliance practice. Greg has substantial expertise in conducting sensitive internal investigations and counseling clients on compliance programs, defending clients in criminal and regulatory proceedings, and serving as trial counsel in complex commercial litigation.

Greg has led domestic and cross-border internal investigations on behalf of a variety of clients across a wide range of industries. He regularly represents clients in investigations led by the Department of Justice, the Securities and Exchange Commission, state attorneys general, and other regulatory bodies.

These matters have involved the FCPA, commercial bribery, the False Claims Act, competition laws, customs laws, US sanctions/OFAC, securities fraud, consumer fraud, tax, money laundering, and environmental offenses. Greg also routinely counsels clients on compliance programs and compliance audits/due diligence arising out of acquisitions and joint ventures.

Greg is a seasoned trial lawyer, having tried many criminal and civil cases in federal and state court and in arbitration, along with serving as lead counsel in numerous criminal and civil appeals. Greg’s complex commercial litigation experience involves various areas of law, including RICO, federal and state securities law, Lanham Act claims, antitrust, tax controversy, environmental law, and shareholder derivative claims.

Prior to rejoining Mayer Brown, Greg served as an Assistant US Attorney in Chicago, assigned to the Public Corruption section. Greg prosecuted numerous public officials and law enforcement officers with fraud, bribery, extortion, and tax offenses, including the bribery prosecution of an Illinois state representative.

His trial experience includes the month-long trial of William Cellini, a long-standing political insider in Illinois convicted of extorting campaign contributions for then Governor Rod Blagojevich.

In addition to his corruption experience, Greg investigated and prosecuted a wide range of federal criminal cases involving complex financial fraud, money laundering, computer offenses and international drug trafficking, including the prosecution of members of the Los Zetas and Sinaloa cartels.

Greg maintains an active pro bono practice, including serving as a Panel Attorney for the Federal Defender Program in Chicago, representing indigent defendants in federal criminal proceedings.

Greg has been an adjunct professor of criminal procedure and trial advocacy at DePaul University College of Law and previously served on Law360’s White Collar Editorial Advisory Board. Greg began his legal career as a law clerk for the Honorable Deanell Reece Tacha, Chief Judge of the US Court of Appeals for the Tenth Circuit.

Education :

  • University of Illinois College of Law, JD, summa cum laude, Order of the Coif, valedictorian
  • Marquette University, BS ,Civil & Environmental Engineering

Admissions : Illinois

Experience :

  • Internal investigation for financial institution into whistleblower allegations of fraud/misconduct in connection with rating foreign currency transactions.
  • Internal investigation for Fortune 500 company into whistleblower allegations of accounting fraud and securities law violations.
  • Internal investigation for Fortune 50 company into allegations that employees made political contributions in exchange for government contracts.
  • Internal investigation for public heavy equipment manufacturer into potential FCPA, antitrust, money laundering and U.S. sanctions violations involving non-U.S. wholly-owned subsidiary and transactions in Egypt, India and Thailand.
  • Internal investigation for public agency into allegations of CEO misconduct in awarding vendor contracts and conflicts of interest.
  • Counsel for Fortune 500 medical device company in parallel DOJ civil/criminal False Claims Act investigation; DOJ declined to intervene.
  • Counsel for public accounting/consulting firm in numerous DOJ criminal/civil investigations, involving alleged bank fraud, AML/BSA violations and False Claims Act claims.
  • Counsel for Fortune 50 financial institution in lawsuits filed around the U.S. relating to allegedly abusive tax shelters.
  • Achieved dismissal of Lanham Act claim arising out of dispute between members of joint venture, which the Seventh Circuit affirmed on appeal.


Rate : $$$

What types of cases Attorney J. Gregory Deis & Mayer Brown can handle?
Mayer Brown can handle cases related to laws concerning Litigation, White Collar Crime, Health Care, Securities Fraud. We manually verify each attorney’s practice areas before approving their profiles and reviews on our website.
Where is Mayer Brown located?
Mayer Brown is located at 71 S Wacker Dr, Chicago, IL 60606, USA. You can reach out to Mayer Brown using their phone line 312.701.8035. You can also check their website mayerbrown.com or email them at [email protected].
How much would it cost to hire Mayer Brown?
J. Gregory Deis lawyer charges are specific to each case. However, they work with contingency fees and its ranges from $$ to $$$. They also provide free consultation [and no obligation quotes] if you are interested to hire.
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