Thomas P O'Brien

Practice Areas

White Collar Defense & Investigations

Litigation

Career

Thomas P. O’Brien advises clients throughout all phases of government investigations and prosecutions encompassing a broad scope of situations such as corporate compliance matters, fraud, and state and federal False Claims Act cases. He serves as both an advocate and counselor for corporations and individuals, guiding them from the start of government interactions to the end of trial proceedings. Tom often carries out internal investigations for corporations and municipal governments with a strategic approach, aiming to prevent clients from potential legal violations or misconduct.

In the field of white collar defense, Tom manages cases of embezzlement, accounting fraud, and bribery, among others, addressing complex and dynamic issues. He represents clients in complex civil actions involving substantial financial amounts and offers advice to foreign state leaders in criminal proceedings. He has robust experience managing cases associated with federal and state False Claims Act statutes (also known as qui tam matters), and the Foreign Corrupt Practices Act. He effectively guides clients through intricate health care fraud issues, as well as other regulatory hurdles.

Tom is a nationally recognized trial attorney. He is a U.S. Fellow with the International Academy of Trial Lawyers, an honor limited to 500 trial attorneys in the United States; a member of the National Trial Lawyers: Top 100; and has been noted by Chambers USA. Tom has tried over 100 criminal and civil cases in federal and state courts throughout the nation. He has represented national and multinational companies in civil actions with billions of dollars in dispute, and has represented individual corporate leaders and foreign heads of state in civil, criminal, and regulatory proceedings. He has deep experience navigating dual civil-criminal proceedings and handling complex, first-of-its-kind matters in multiple jurisdictions, including matters conducted in foreign nations.

Tom previously served as United States Attorney for the Central District of California, a position to which he was appointed by President George W. Bush and unanimously confirmed by the United States Senate. During his term, he oversaw all federal criminal and tax investigations and prosecutions, in addition to all civil matters involving the United States, within the largest federal district in the nation. Under his leadership, his office filed record-breaking felony cases and increased complex case filings by 50 percent, including significant progress in prosecuting organized crime. The office filed the largest gang RICO case in the history of the Department of Justice, the largest RICO case against a motorcycle gang and, for the first time in the nation, seized the gang’s trademark. His office also filed the largest tax restitution case in IRS history.

Before his confirmation as United States Attorney, Tom served as Chief of the Criminal Division for over two years. In this role, he was responsible for several high-profile espionage cases, helped bring the first treason case in the country since World War II, supervised multiple public corruption and civil rights cases, and oversaw some of the largest fraud cases prosecuted in the United States.

Before being selected as Criminal Chief, Tom led the office’s Civil Rights Section, where he investigated and prosecuted numerous cases, including federal hate crimes, human trafficking offenses, and police and prison guard misconduct cases.

Tom’s prosecutorial career began in San Diego County before moving to Los Angeles County as a Deputy District Attorney assigned to the Hardcore Gang Division, where he tried 35 gang murder cases.

After graduating from the United States Naval Academy, he served in the United States Navy as a Radar Intercept Officer in the F-14A Tomcat fighter, completing over 2,000 flight hours and two overseas deployments on active duty. He is a graduate of the United States Navy Fighter Weapons School commonly known as TOPGUN.

Professional Memberships

Member, Trial Law Institute

Member, Diversity Law Institute

Member, National Association of Criminal Defense Lawyers

Former Vice-Chair, ABA Section of International Law, International Anti-Corruption Committee, Steering Committee, Asia Regional Forum

Former Member, Legal Advisory Committee for the Anti-Defamation League

Former Board Member, Chandler School in Pasadena, California

Former Chair, Attorney General’s Advisory Committee’s Cyber/Intellectual Property Subcommittee

Former Board Member, Legal Aid Foundation of Los Angeles (LAFLA)

Personal

J.D., cum laude, University of San Diego School of Law; Associate Editor, San Diego Law Review

B.S., U.S. Naval Academy