Partner
Government Investigations & White Collar Criminal Defense
“Piloting clients and their corporate entities through the tumultuous and complex waters of internal and government investigations is our role and one that I find incredibly rewarding.”
Zachary (“Zach”) Terwilliger, a highly ranked Chambers white collar practitioner and the former Senate-confirmed United States Attorney for the Eastern District of Virginia, brings both extensive frontline experience across all manner of complex investigations at the Department of Justice and a substantial record of high-profile private practice representations. Those frontline skills combine with his mastery of strategy, problem solving, and crisis management—skills honed by prosecuting multi-national complex cases and then serving in the highest levels of the Department of Justice and leading one of the most prominent U.S. Attorney’s Offices in the country. Since entering private practice, Zach has firmly established himself as go-to counsel on a series of complex and high profile representations. His representations—spanning top corporate clients as well as C-suite executives and other prominent officialshave earned consistent market recognition, including rankings in the Global Investigations Review 100, and selection to the elite GIR 30,The Best Lawyers in America for False Claims Act, and as part of The 500 Leading Litigators in America and The 500 Leading Cybersecurity Lawyers in the World, and the 500 Global Leaders in Crisis Management by Lawdragon, as well as the previously mentioned Chambers USA, where he is now ranked with those who are a decade or more his senior.
Represented a cabinet-level official in connection with congressional investigation before U.S. Congress
Represented a major medical center in a highly complex and novel FCA settlement with the U.S. Department of Justice
Led sensitive investigation of mass shooting event at major university
Assisted a defense contractor in responding to a significant cyber incident including with respect to reporting obligations to DoD
Representing a Silicon Valley-based technology company in internal and governmental investigations both domestically and in Asia
Representation of large corporate entity through multi-year investigation to resolution via Deferred Prosecution Agreement
Representation of large government contractor regarding cybersecurity compliance and False Claims Act allegations
Highly sensitive internal investigation at the C-Suite level for major U.S. Company that resulted in leadership change
Representation of Fortune 100 company across wide swath of investigations to include white collar, environmental, and antitrust
Representation of major sports franchise across multiple enforcement inquiries and internal investigations
Act as pool counsel to multiple executives related to wide range DOJ criminal probe
Individual representation of CEOs, CFOs, GCs, and other C-Suite executives who are witnesses, subjects, or targets of federal and state investigations
Representing high-profile former government principals before Congressional Committees and the Department of Justice
Representing an association with a membership that exceeds 300,000 in response to government inquiry
Representing a publicly traded financial services company in connection with Department of Justice grand jury investigation
Representing a major university system in connection with an investigation by Congress and a state legislature
Representing C-Suite individuals in an ongoing DOJ and internal investigation probe
Representing a large corporate entity in connection with Department of Justice False Claims Act investigation
Crisis counseling and representing a large government contractor regarding employee misconduct and theft of intellectual property
Serving as deputy to court appointed monitor in five-year monitorship following shareholder suit settlement
Representing primary collective for Division I Football Program in NCAA Name, Image, and Likeness “NIL” Investigation
Representing a corporate entity in DOJ FCPA investigation
Representing a corporate entity before state Attorneys General as it pertains to allegations of violation of consumer protection statutes
(E.D. Va.) – Led investigation and prosecution of nationwide fraud where the defendants deceived struggling homeowners through false representations regarding the U.S. Government’s Troubled Asset Relief Program via the Home Affordable Modification Program (“HAMP”). In partnership with the Special Inspector General for the Troubled Asset Relief Program, the individuals were convicted
(E.D. Va.) – Led investigation and prosecution of insurance fraud and arson whereby a major commercial building was damaged by fire to conceal other crimes. The case involved multiple experts, complex science, and forensic accounting. Ultimately, the defendant was convicted at trial
(E.D. Va.) – Led investigation of public official who was misusing his office to benefit another in exchange for gifts, access, and other illicit benefits. The defendant was convicted
(E.D. Va.) – Led investigation of racketeering case involving organized crime with multiple defendants who were engaged in extortion, human trafficking, violence, and drug trafficking. The defendants were ultimately convicted at trial
(E.D. Va.) – Supervised multiple corporate resolutions involving hundreds of millions of dollars. These cases involved close coordination with outside counsel, the Department of Justice Fraud Section, and Criminal Division leadership
(E.D. Va.) – Led entire U.S. delegation for presidential level meetings with the Government of Colombia. Responsible for addressing and briefing the Colombian President and his cabinet at the presidential palace regarding the U.S. commitment and strategy to combat narco-terrorism. In addition, participated as the sole U.S. representative in nationally broadcast presidential address from dual podiums with the Colombian President to reassure the citizens of Colombia regarding our commitment to jointly fighting narco-terrorism and corruption
Education
Admissions
Client Alerts
After the Midterms: Preparing for a New Era of Congressional Oversight
Following the November 2026 midterm elections, Democrats will control both the House and the Senate when the 120th Congress convenes …
November 5, 2026
November 5, 2026 • 5-minute read
Client Alerts
On September 1, 2026, the United States Court of Appeals for the Eleventh Circuit issued its widely anticipated decision in …
September 3, 2026
September 3, 2026 • 8-minute read
Client Alerts
In a busy week of major policy changes for the Department of Justice (“DOJ” or the “Department”), Assistant Attorney General …
August 26, 2026
August 26, 2026 • 8-minute read
Articles
5 Strategies to Reduce the Risk of a DOJ False Claims Act Investigation
The Department of Justice (DOJ), via messaging from its leadership, has made clear it will prioritize and pursue aggressive civil False Claims Act (FCA) enforcement against companies that receive federal dollars. As the government’s primary civil remedy to redress fraud against the government, the FCA generates billions of dollars in annual DOJ settlements and judgments with the majority initiated by whistleblower qui tam lawsuits.
August 17, 2026
August 17, 2026 • 2-minute read
Client Alerts
Beyond the Trading Window: Why Prediction Markets Are the Next Frontier of Insider Trading Risks
Corporate legal departments at public and private companies are confronting a novel insider trading problem — one for which their …
June 25, 2026
June 25, 2026 • 16-minute read
