Recognized as “a rising star in the white-collar litigation market,” with one reviewer commenting: “‘I’ve been impressed with Greg’s advocacy in the courtroom and his handling of the significant investigation issues which come up along the way.’”
Chambers USA 2019

Overview

Greg Deis is a former federal prosecutor and co-chair of Mayer Brown's White Collar Defense & Compliance practice. Greg's practice focuses on leading internal investigations and defending clients in criminal and regulatory proceedings. Greg is also a seasoned trial lawyer, having served as lead trial counsel in numerous trials and arbitrations, both as a prosecutor and in private practice.

Greg has led domestic and cross-border investigations on behalf of a variety of clients across a wide range of industries. He regularly represents corporate and individual clients in investigations led by the US Department of Justice, the Securities and Exchange Commission, state attorneys general and other regulators. These matters have involved investigations of alleged violations of the FCPA and public corruption, commercial bribery, insider trading, accounting fraud, US sanctions, the False Claims Act, antitrust, customs, tax, money laundering and environmental offenses. Greg also counsels clients on compliance programs and due diligence relating to acquisitions and joint ventures.

Greg's complex commercial litigation experience involves various areas of law, including RICO, federal and state securities law, the Lanham Act, antitrust, breach of contract, tortious interference with contract and environmental law. Recent civil trials include a multi-week securities fraud trial in Delaware Chancery Court (favorable settlement post-trial); a two-week arbitration representing an AmLaw 20 law firm (tribunal award in client's favor); defending a Big Four accounting firm in an arbitration brought by a former employee (tribunal dismissed all claims); and defending an international accounting firm in a two-week arbitration against claims of fraud and malpractice in connection with a financial statement audit (decision pending).

Prior to rejoining Mayer Brown in 2013, 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. Greg served as trial counsel in over a dozen criminal jury trials, including the month-long trial of William Cellini, a longstanding 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. For example, Greg prosecuted high-ranking members of both 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 is recognized by Chambers USA 2019 as an “Up and Coming” lawyer in White Collar Crime and Government Investigations in Illinois. He 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.

Highlights
Securities Investigations: Internal, Civil and Criminal

Experience

Representative experience includes:

Internal Investigations/Compliance

  • Internal investigation for a Fortune 500 company into whistleblower allegations of accounting fraud and securities law violations; SEC investigation closed with declination.
  • Investigation for a Fortune 500 subsidiary into whistleblower allegations of improper accounting at UK subsidiary.
  • Internal investigation for a Fortune 500 financial institution into whistleblower allegations of fraud in connection with rating foreign currency transactions involving New York, London and Hong Kong trading desks.
  • Internal investigation for a Fortune 50 company into public corruption allegations involving political contributions and state government contracts.
  • Internal investigation for a Fortune 500 company into alleged corrupt payments and entertainment through third-party intermediary in Japan.
  • Internal investigation for a Fortune 500 consumer goods company into allegations of OFAC Iran sanctions violations.
  • Internal investigation for a public heavy equipment manufacturer into potential FCPA, antitrust, money laundering and US sanctions violations involving a non-US wholly-owned subsidiary and transactions in Egypt, India and Thailand.
  • Internal investigation for a public heavy equipment manufacturer into potential FCPA violations involving a wholly-owned subsidiary and transactions in the UAE.
  • Internal investigation for construction equipment supplier into allegations of commercial bribery and bid rigging through UK third-party intermediary for Netherlands-based project.
  • Internal investigation for a processed food supplier into allegations of customs violations.
  • Internal investigation for a public energy company into allegations of conflicts of interest, undisclosed related-party transactions, misappropriation of corporate opportunities and antitrust violations, by the CEO and chairman of the board of directors.
  • Internal investigation for a national home improvements/furnishings provider into allegations of conflicts of interest, undisclosed related-party transactions and self-dealing by the CEO/board member.
  • Internal investigation for a public agency into allegations of CEO misconduct in awarding vendor contracts and conflicts of interest.
  • Internal investigation for a charter school operator involving alleged improper payment by a third-party vendor; represented client in related SEC and IG investigations.
  • Internal investigation for a public company into allegations of insider trading involving board of directors members.
  • Internal investigation for a Fortune 500 company into allegations that the CEO of the company's foreign subsidiary misappropriated trade secrets from a former employer.
  • Routinely advise clients in various industries on anti-corruption due diligence and compliance policies and procedures, including those arising out of proposed acquisitions or joint ventures.

White Collar Defense

  • Fortune 500 medical device company in a parallel DOJ civil/criminal False Claims Act investigation; DOJ declined to intervene.
  • Fortune 50 financial institution in a DOJ investigation involving allegedly abusive tax shelters; no charges against client.
  • Fortune 50 company in an SEC investigation regarding alleged accounting fraud; obtained no action letter following Wells submission.
  • Construction company in an Illinois Attorney General's Office consumer fraud investigation.
  • Fortune 500 company in a Texas Attorney General's Office consumer fraud investigation.
  • Public international hotel group in connection with a DOJ and internal investigation of a terrorist attack in Mali.
  • Oil-and-gas company in a DOJ criminal environmental investigation.
  • Private equity client in a DOJ AML investigation arising out of alleged bribery and money laundering in Peru.
  • Senior engineer in the DOJ’s GM ignition switch investigation.
  • Senior engineer in the investigations by the DOJ and German prosecutors into Audi emissions.
  • Alleged tippee in DOJ and SEC insider trading investigation.
  • Registered broker in CFTC and DOJ investigation of fraud and unauthorized trading.
  • Trading firm in CFTC investigation of alleged manipulative trading practices.
  • Numerous hospital executives, including CFO, in a DOJ False Claims Act investigation arising out of a hospital-physician joint venture.
  • Steel distributor in an SFO investigation involving alleged financial fraud.
  • Public accounting/consulting firm in numerous DOJ criminal/civil investigations, involving alleged bank fraud, AML/BSA violations and False Claims Act claims.
  • Fortune 500's former general counsel in an SEC investigation regarding alleged accounting fraud.
  • Fortune 50 joint venture's general counsel in a DOJ/SEC FCPA investigation of alleged improper payments in India.
  • Fortune 500's former general counsel in a DOJ/SEC FCPA investigation regarding alleged improper payments in Brazil.
  • International PR firm's CFO in a DOJ FCPA investigation regarding alleged improper payments, travel and entertainment in China.
  • Fortune 50 senior executive in a DOJ and SEC FCPA investigation regarding alleged improper payments in Brazil.
  • Private equity portfolio company officer in a parallel DOJ and SEC investigation of alleged securities fraud.
  • Physician and executive director in a parallel DOJ criminal and civil False Claims Act investigation.
  • Corporate executive in a successful Seventh Circuit appeal of a federal criminal sentence for conversion/embezzlement.

Complex Commercial Litigation

  • Counsel for international accounting firm in two-week arbitration alleging malpractice in connection with financial statement audit; decision pending.
  • Counsel for a Big 4 accounting firm in an arbitration involving a former employee alleging tortious interference with contract and defamation; tribunal award in client’s favor denying all claims. 
  • Counsel for an AmLaw 20 international law firm in a two-week arbitration against a software developer; tribunal award in client's favor.
  • Counsel for an officer of a private equity portfolio company in a Delaware Chancery Court trial involving allegations of, inter alia, securities fraud; case settled following a multi-week trial. 
  • Counsel for two "affiliates" of Sprint in high-stakes trials challenging Sprint's conduct following the Sprint-Nextel merger. The clients obtained favorable judgments in two separate trials in Delaware and Illinois. In Illinois, the client secured an injunction requiring that Sprint cease operating its Nextel business in the client's territory. In Delaware, the client secured an injunctio prohibiting Sprint from using Sprint trademarks to promote Nextel products in the client's territory. 
  • Counsel for a Fortune 50 financial institution in a RICO and fraud action; obtained summary judgment arguing successfully against direct fraud and respondeat superior liability.
  • Counsel for a public energy company in a federal RCRA environmental action; obtained dismissal on 12(b)(6) grounds based on RCRA issues of first impression in the Seventh Circuit. 
  • Counsel for a public international hotel group in a federal suit seeking damages based on former Yugoslavia's nationalization of plaintiff's ancestors' property in present-day Serbia; obtained dismissal on forum non conveniens grounds.
  • Achieved dismissal of a Lanham Act claim arising out of a dispute between members of a joint venture, which the Seventh Circuit affirmed on appeal.
  • Achieved dismissal of a $110 million defamation suit brought by a former Illinois Appellate Court judge and candidate for the Illinois Supreme Court against a political action committee and several individuals. The trial court decision was affirmed by the Illinois Appellate Court and the Illinois Supreme Court.
  • Counsel for a health care insurance broker in a federal Lanham Act case.
  • Counsel for a public technology company in a case involving allegations of breach of contract, Lanham Act and Sherman Act claims.
  • Counsel for a Fortune 50 financial institution in lawsuits filed around the US relating to allegedly abusive tax shelters.

Education

University of Illinois College of Law, JD, summa cum laude

Order of the Coif, valedictorian

Marquette University, BS, Civil & Environmental Engineering

Admissions

  • Illinois