
Patrick O'Brien
Managing Partner
707-789-6500 phone
707-789-6520 fax
Patrick O’Brien owns and manages the boutique California law firm O’Brien Law, P.C.
Mr. O’Brien received his undergraduate degree from Loyola Marymount University and his law degree from Gonzaga Law School where he was Associate Editor of the Gonzaga Law Review. Mr. O’Brien has also completed his LLM in Negotiation and Dispute Resolution from Pepperdine School of Law and graduated Summa Cum Laude.
O’Brien Law, P.C. focuses on general civil litigation with an emphasis on major litigation and trials, business and trust matters and corporate general counsel work. Mr. O’Brien’s trial and litigation experience includes cases involving complex construction, automobile, product liability, professional liability, business, probate, insurance, elder abuse, employment and business fraud and forensic accounting matters. In eight years the firm has grown from two attorneys to ten attorneys, making the firm one of the largest law firm north of San Francisco according to the North Bay Business Journal. The firm’s clients include Hanford Restoration Company, Execushield Security, Grech Motors, Hartford Insurance, State Farm Insurance Company, Korbel Winery, The Argo Group of Insurance Companies, World Oil Company, Lancer Insurance, Global Liberty Insurance, Sompo Insurance, National Claims Services and many others. The firm maintains offices in Northern California, the Central Valley and Southern California.
Prior to founding O’Brien Law, Mr. O’Brien worked at Ropers, Majeski as a senior associate and then was a partner at Lanahan & Reilley and Daniel Crowley & Associates.
In addition to litigation, Mr. O’Brien advises a number of companies in an outside general counsel capacity. These companies are located throughout the State of California and engage in a broad range of activities from hotels to construction to RV manufacturers.
Mr. O’Brien is a member of the Sonoma County, San Francisco County, San Mateo County, Los Angeles County and Orange County Bar Associations. He is admitted to practice law in all of the State and Federal Courts in California and is admitted to argue before the United States Supreme Court.
Mr. O’Brien has been recognized by his peers with a number of award. He has also been included in the prestigious Irish Legal 100 list for the past five years. This list includes Supreme Court justices, federal judges and the top attorneys in the country. Mr. O’Brien has also been recognized as a top elder abuse attorney in the state. In addition, Mr. O’Brien was added to the Superlawyers of Northern California list in 2023.
In addition to his extensive legal background, Mr. O’Brien has served as CEO, General Counsel and Board Member for several companies in the United States, the United Kingdom and Central America. Because of his business background, Mr. O’Brien is regularly hired to prosecute or defend matters involving complex forensic accounting. Most recently Mr. O’Brien has been hired by several local governments in California to recover millions of dollars for their utility rate payers. These lawsuits have resulted in the recovery of over 15 million dollars for the ratepayers in those communities.
Mr. O’Brien’s writings on legal, safety and employment issues related to transportation are regularly published in multiple transportation industry related journals. He is also asked to speak at transportation conventions throughout the United States. Mr. O’Brien has been General Counsel of the Greater California Livery Association for the past five years and has also provided legal advice to the National Limousine Association.
The O’Brien Family is committed to public service. Mr. O’Brien’s brother, Robert O’Brien, served as the United States National Security Advisor from 2019 to 2021. Patrick O’Brien has also been committed to public service his entire life.
For example, in 2019 Mr. O’Brien was elected to a four-year term to serve on the Board of Advisors for the International Development Law Organization. IDLO is the only NGO which promotes the rule of law throughout the World. The Board meets each year in Rome, Italy to provide guidance to IDLO. IDLO operates in over 90 countries worldwide with a focus on human rights, due process and constitutional and judicial reforms. Examples of IDLO’s current programs include strengthening government response to domestic violence in Mongolia, supporting access to justice in Afghanistan and combating corruption in the Ukraine, Somalia and the Bahamas.
An interesting sidelight to Mr. O’Brien’s career is that he was a professional child actor. Beginning at age 8, he appeared in over 40 stage shows, including San Francisco Opera’s “Lost in the Stars” and the Broadway version of “Evita.” He also had a distinguished television career which included appearances in television movies, such as Emmy Award winning drama, “Something About Amelia,” TV series, such as ”Father Murphy” and “Easy Street,” and many national television commercials for such brand as Pepsi and Close Up Toothpaste. Mr. O’Brien remains a member of Screen Actors Guild and Actor’s Equity.
Recent Articles Authored By Mr. O’Brien Include:
- Liability Waiver: Transferring the Risk to the Passenger
- Common Carriers: Not Insurers of Passenger Safety
- Strategies for Being Safe with Affiliates
Areas of Law
- General Civil Litigation
- Franchise Law
- Business Litigation
- Premises Liability
- Personal Injury
- Products Liability
- Labor & Employment
A Member Of:
- National Limousine Association
- Greater California Livery Association, Member of the Board of Directors, 2016-17
- State of California Bar Association, Employment Law Section, Litigation Section
- Honoree, Irish Legal 100, 2017
- Board of Advisors for the International Development Law Organization
Admission Details
- Admitted in 1993, California
-
US Supreme Court, admitted 2018
Law Schools Attended
- Gonzaga University, Class of 1993, J.D.
- Pepperdine University School of Law, 2022, LLM
University Attended
- Loyola Marymount University, Class of 1990, B.A.
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Kathleen Miller
Partner
707-789-6500 phone
707-789-6520 fax
Kathleen C. Miller has been a member of the California Bar since 1999 and a member of the Texas Bar since 1991. She is a partner at O’Brien Law, PC and chairs the firm’s construction defect practice.
Her focus is on general commercial litigation with an emphasis on construction, real estate, contracts, employment and probate litigation. She has successfully tried multiple cases, argued twice successfully in front of the Court of Appeals, and participated in numerous arbitration proceedings, mediations and administrative law hearings. She has also served as a Judge Pro Tem for the Sonoma County Superior Court.
In addition to her work with the firm, she is the President of the Board of the Petaluma Policing Foundation, a member of the Sonoma County Bar Association and a member of the Petaluma Area Chamber of Commerce, where she sits on the Government Affairs Committee and participates in the Petaluma Business Alliance.
She previously served for eight years as a member of the Petaluma City Council. During her time on the City Council, she was on the Board and Executive Board of the Sonoma County Transportation Authority and the Regional Climate Protection Authority as well as the Council liaison to many City Commissions and Committees.
Areas of Law
- Commercial Litigation
- Labor and Employment Litigation
- Real Estate Litigation
- Construction Litigation
- Probate Litigation
A Member Of:
- California Bar Association
- Texas Bar Association
- Sonoma County Bar Association
Law Schools Attended
- University of San Francisco
University Attended
- University of Texas
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Steve Pabros
Partner
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707-789-6520 fax
Steve Pabros has been a trial attorney for the last 35 years. During that time he has completed 100 personal injury jury trials and 16 bench trials. He has been lead counsel in civil jury trials in fourteen California counties, including San Francisco, Los Angeles, San Mateo, Stanislaus, Kern, San Bernardino, Mendocino, Alameda, Contra Costa, Marin, Solano, Sonoma, Napa, and Lake County.
Prior to joining O’Brien Law P.C., Mr. Pabros was Senior Trial Attorney at Farmers Insurance Group for 8 years. Prior to that Mr. Pabros was a trial attorney for Allstate Insurance Company for 15 years. Steve brings a wealth of litigation experience to the firm and can handle all types of litigation including fire claims, personal injury, product liability and construction defect.
Mr. Pabros earned his BA from UC Santa Cruz in Economics and his JD from Empire Law School
Areas of Law
- General Civil Litigation
A Member Of:
- California Bar Association
Law Schools Attended
- Empire College School of Law
University Attended
- University of California, Santa Cruz
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Caitlin Phair
Partner
707-789-6500 phone
707-789-6520 fax
Caitlin Phair has been a member of the California State bar since 2015. Her practice focuses primarily on general civil litigation. Prior to joining the firm, Ms. Phair worked as a real estate litigation attorney and has extensive experience representing Clients in both State and Federal courts, as well as, arbitrations and multi-party mediations. Her writing, research, and oral advocacy skills have resulted in numerous successful cases for Clients both nationally and internationally.
Ms. Phair received a B.A. from Loyola Marymount University where she was a member of the Delta Zeta Sorority and Co-President of the club water polo team. She obtained her J.D. from the University of San Francisco School of Law in 2014 where she was the winner of the First Year Moot Court Competition, a member of the Jessup Moot Court Competition Team and received the inaugural Dean Brand Pursuit of Justice Fellowship.
Following graduation Ms. Phair worked as a Legal Advocate in Thailand providing direct services to asylum-seekers and refugees. Her drive, compassion and dedication to helping those in need is what makes her a compelling advocate.
In her spare time, Ms. Phair enjoys rooting for the San Francisco 49ers and playing with her frenchie Jax.
Areas of Law
- General Litigation
- Probate Litigation
- Insurance Defense
- General Counsel
A Member Of:
- California Bar Association
Admission Details
- Northern and Eastern District Courts of California
Law Schools Attended
- University of San Francisco School of Law – JD and International and Comparative Law Certificate
University Attended
- Loyola Marymount University – BA in Political Science
Your direct Message to Caitlin Phair

James Choo
Senior Attorney
707-789-6500 phone
707-789-6520 fax
James Choo is an attorney with the firm as a civil litigator and handles matters throughout the State of California.
His practice focuses primarily on general civil litigation. He has extensive experience with construction defect, personal injury, products liability and business litigation. He has also represented multiple subcontractors, general contractors and developer defendants in complex litigation construction cases.
Mr. Choo is admitted to practice before all California courts, the United States District Court for the Northern District of California and the Ninth Circuit Court of Appeals.
Mr. Choo also served as a first lieutenant in the U.S. Army.
Mr. Choo received his B.A. from the University of California, Berkeley. He received his J.D. from the University of Tulsa College of Law.
In his free time, Mr. Choo enjoys skiing, trail running, Cal football and San Jose Sharks hockey.
Areas of Law
- Construction Defense
- General Civil Litigation
A Member Of:
- California Bar Association
Law Schools Attended
- University of Tulsa College of Law
University Attended
- University of California, Berkeley
Your direct Message to James Choo

Bridget K. Riley
Senior Attorney
707-789-6500 phone
707-789-6520 fax
Bridget K. Riley joined O’Brien Law, P.C. an Associate Attorney in 2024.
Bridget graduated from University of California at Davis in 1995 where she obtained a Bachelor of Arts degree in Economics. She obtained her Juris Doctor from the University of McGeorge School of Law and was admitted to the State Bar of California in 2000.
During her law school career, Bridget represented McGeorge in several mock trial competitions, winning a highly competitive Regional Mock Trial competition. She and her team moved on to the Mock Trial Finals in Washington D.C. where she had the honor and privilege of personally meeting Supreme Court Justice Anthony Kennedy at the United States Supreme Court.
Bridget began her legal career with the Marin County District Attorney’s Office in 2000, successfully prosecuting over two dozen cases on behalf of the People of California. She entered private practice between 2008 and 2010, and then paused her legal career to become a real estate investor and interior design consultant.
Bridget returned to the practice of law in 2024 at O’Brien Law, P.C. where she practices civil litigation. She is a member of the Sonoma County Bar Association. When not practicing law, Bridget enjoys international travel, photography, and ceramics as a hobby.
Areas of Law
- General Civil Litigation
- Insurance Defense
- Contractor Liability
A Member Of:
- California Bar Association
Law Schools Attended
- University of McGeorge School of Law
University Attended
- University of California, Davis
Your direct Message to Bridget K. Riley

Kharman Aidun
Attorney
707-789-6500 phone
707-789-6520 fax
James Choo is an attorney with the firm as a civil litigator and handles matters throughout the State of California.
His practice focuses primarily on general civil litigation. He has extensive experience with construction defect, personal injury, products liability and business litigation. He has also represented multiple subcontractors, general contractors and developer defendants in complex litigation construction cases.
Mr. Choo is admitted to practice before all California courts, the United States District Court for the Northern District of California and the Ninth Circuit Court of Appeals.
Mr. Choo also served as a first lieutenant in the U.S. Army.
Mr. Choo received his B.A. from the University of California, Berkeley. He received his J.D. from the University of Tulsa College of Law.
In his free time, Mr. Choo enjoys skiing, trail running, Cal football and San Jose Sharks hockey.
Areas of Law
- Construction Defense
- General Civil Litigation
A Member Of:
- California Bar Association
Law Schools Attended
- University of Tulsa College of Law
University Attended
- University of California, Berkeley
Your direct Message to Kharman Aidun

Alexander Nguyễn
Attorney
707-789-6500 phone
707-789-6520 fax
Alexander Nguyễn received his undergraduate and graduate degree from San Francisco State University. Mr. Ngyuễn received his juris doctorate from the University of San Francisco School of Law.
In addition to working with O’Brien Law, P.C., Mr. Ngyuễn volunteers for non-profit organization and has dedicated himself to community service. His practice at O’Brien Law, P.C., focuses on general civil litigation, including person injury insurance defense, business litigation, and probate litigation.
Mr. Ngyuễn believes his passion for community service and helping others is an invaluable asset in his practice of law that sets him apart from other attorneys.
Areas of Law
- Personal Injury
A Member Of:
- California Bar Association
Law Schools Attended
- University of San Francisco School of Law
University Attended
- San Francisco State University