Co-Founder | National Security Law Attorney
Former INSCOM Intelligence Law Attorney and Army Reserve Judge Advocate With Full-Time Experience at the Defense Office of Hearings and Appeals
Brett J. O’Brien has spent his career working inside the federal systems that investigate, evaluate, and adjudicate national-security risk. His government experience includes service with both the United States Army Intelligence and Security Command and the Defense Office of Hearings and Appeals, giving him an unusually broad perspective on how security concerns are investigated, developed, and ultimately decided.
While serving as a Judge Advocate in the United States Army Reserve, Brett completed a full-time assignment with the Defense Office of Hearings and Appeals (DOHA). DOHA conducts hearings and appellate review in security-clearance cases involving government contractors and performs other adjudicative functions for the Department of Defense.
Working inside DOHA gave Brett direct experience with the office responsible for deciding some of the federal government’s most consequential security-clearance cases. He gained firsthand insight into DOHA procedures, the development of the administrative record, and the way security concerns, credibility, mitigation, and evidentiary issues are evaluated throughout the adjudicative process.
Brett also served as an Intelligence Law Attorney for the United States Army Intelligence and Security Command (INSCOM), where he advised military leaders, intelligence professionals, and government officials on highly sensitive intelligence, counterintelligence, personnel-security, and national-security matters.
As the primary legal advisor for active Army counterintelligence investigations, Brett worked closely with the Federal Bureau of Investigation, National Security Agency, Defense Intelligence Agency, Department of the Treasury, and other members of the Intelligence Community. He advised on counterintelligence operations, personnel-security concerns, intelligence oversight, classified-information issues, cyber matters, government investigations, and the legal authorities governing national-security operations.
This combination of investigative and adjudicative experience is particularly valuable in security-clearance cases. Brett understands how potentially adverse information is identified and investigated, how it becomes part of the government’s record, and how that record may later be evaluated by adjudicators and administrative judges.
His experience helps clients address more than the immediate allegation. It allows him to identify how an explanation may be interpreted, whether the available evidence resolves the government’s actual concern, where credibility problems may arise, and how statements made at one stage can affect a later Letter of Interrogatory, Statement of Reasons, hearing, appeal, reinvestigation, or continuous-vetting review.
In addition to his assignments with INSCOM and DOHA, Brett served as an Army Reserve Judge Advocate and rose to the rank of Major. His military legal experience included military justice, administrative law, ethics, federal employment matters, Equal Employment Opportunity issues, Merit Systems Protection Board litigation, and federal litigation support.
Brett also served as an Adjunct Professor teaching Cyber Ethics and has instructed national-security attorneys on intelligence law and intelligence-oversight matters.
As co-founder of National Security Law Firm, Brett has played a central role in building the firm’s national-security practice and multidisciplinary approach. He helped develop a firm designed for clients whose problems do not remain confined to a single government system.
A security incident may simultaneously affect a clearance, federal employment, military status, facility access, professional credentials, or a government investigation. Drawing on his experience across intelligence, counterintelligence, security-clearance adjudication, military law, and federal administrative practice, Brett has helped assemble a team capable of evaluating those overlapping consequences together.
Under Brett’s leadership, National Security Law Firm has grown into a nationwide federal practice that includes former judges, prosecutors, security-clearance adjudicators, national-security counsel, military officers, government investigators, and federal agency attorneys. The firm represents clients in security-clearance matters, military proceedings, federal employment disputes, government investigations, credentialing and access cases, veterans matters, immigration proceedings, and other cases involving government trust and risk determinations.
Today, Brett focuses his practice on security-clearance matters—including SF-86 reviews, Letters of Interrogatory, Statements of Reasons, DOHA hearings, appeals, and revocations—as well as counterintelligence and administrative investigations, federal employment matters, military law, credentialing cases, and other proceedings involving government assessments of trustworthiness, judgment, reliability, and national-security risk.
Government Experience
- Full-time Army Reserve assignment with the Defense Office of Hearings and Appeals
- Intelligence Law Attorney, U.S. Army Intelligence and Security Command
- Primary legal advisor for active Army counterintelligence investigations
- U.S. Army Reserve Judge Advocate, Major
- Advisor on personnel security, intelligence oversight, classified information, cyber matters, and national-security operations
- Federal employment, EEO, MSPB, ethics, military justice, and administrative-law experience
Jurisdictions Admitted: New York, Ohio, New Jersey, and the District of Columbia. Brett represents clients nationwide in federal administrative, military, security-clearance, intelligence, and national-security matters.
Education: J.D., Case Western Reserve University School of Law; B.A., Economics and History, Denison University.