Lynne M. Halbrooks

Lynne M. Halbrooks

Lynne Halbrooks joined Cassidy Law in May 2025. She provides practical advice to individuals and organizations to help them manage their legal, compliance, and enforcement risks.

Lynne advises clients on all aspects of government compliance and represents them in internal and government investigations and audits, including whistleblower reprisal investigations and suspension and debarment proceedings. She has advised companies and individuals on matters involving the False Claims Act, conflicts of interest, counterfeit parts, labor charging disputes, bribery and kickbacks, the Foreign Corrupt Practices Act, responses to subpoenas, and mandatory disclosures.

Prior to joining Cassidy Law, Lynne worked as the Chief Compliance Officer and Deputy General Counsel at Acuity International and was a partner at Nichols Liu LLP and Holland & Knight. Her government service includes leadership roles at the Department of Defense Office of Inspector General, the Special IG for Iraq Reconstruction, the U.S. Senate Sergeant at Arms, and the Department of Justice.

Lynne is a chapter co-author of the ABA-published book, The False Claims Act and Government Contracts, The Enforcement Community, 2022, and a vice-chair of the Public Contract Law Section’s Procurement Fraud and False Claims Act Committee. Throughout her career she has written and spoken extensively on federal contract and grant compliance and enforcement issues.

Lynne earned a B.S. from the University of Minnesota, Duluth and graduated from Marquette University Law School. She is a Member of the District of Columbia, Wisconsin (inactive), and Minnesota (inactive) bars. She also serves on the Boards of Northern Virginia Family Services and the National Center for State Courts.

Representative Matters

• Negotiated an Administrative Agreement with the Department of Navy for a Company and its affiliates in response to a Notice of Proposed Debarment.

• Served as the Independent Monitor for an Administrative Agreement with the Environmental Protection Agency. 

• Resolved False Claims Act allegations of overbilling on a Defense contract through federal district court mediation. 

• Conducted a cross-border investigation into allegations of fraud and concerns about the contractor’s work environment, provided recommendations that were implemented, and persuaded USAID’s contracting office and the OIG not to take adverse action. 

• Successfully responded to a Notice to Show Cause and persuaded the Department of the Navy not to debar a defense contractor accused of retaliating against a whistleblower.  
• Successfully advocated for the lifting of an exclusion for an individual proposed for Debarment by the Defense Health Agency related to allegations of grant fraud. 

• Conducted an internal investigation related to theft of government funds on a USAID project and successfully resolved the matter with a voluntary disclosure and repayment of funds.

• Conducted an assessment of a major private University’s compliance program and provided recommendations for improvements. 

• Successfully represented a retired Army General in a DoD Inspector General investigation by the Defense Criminal Investigative Service after accusations were made that he engaged in a conflict of interest.  The government declined to pursue the matter. 

• Represented a government contractor in the investigation and resolution of a False Claims Act lawsuit filed by a former employee and the subsequent Notice to Show Cause issued by the HHS Suspension and Debarment official. 

• Conducted an assessment of a small government contractor’s Ethics and Compliance program and recommended a structure and program elements suitable for the company’s risk portfolio. 

• Conducted an internal investigation for a manufacturing company and responded to a Defense Criminal Investigative Service subpoena related to a Defense Logistics Agency procurement. 

• Conducted an internal investigation into labor mischarging for a major Defense contractor. 

• Successfully represented a senior Air Force official being investigated by the Air Force Office of Special Investigations for conflicts of interest.  The government declined to pursue the matter. 

• Prepared and represented corporate officials interviewed by Army Criminal Investigative Service agents about counterfeit parts found in the company’s products. 

• Conducted an internal investigation for a major Defense Contractor on potential violations of the Defense Production Act.  

• Represented a government contractor in its response to a subpoena from the National Geospatial Agency.

• Represented a physician employed by a government contractor who was interviewed by DCIS in connection with a patient death. No further action was taken. 

• Conducted an internal investigation for a Defense contractor after allegations were made about staff receiving kickbacks from vendors in Afghanistan. 

• Represented a former employee of a municipality under investigation by the Department of Justice for violations of the False Claims Act.