Gerald L. McMahon
Shareholder, Chairman of the Firm & Family Law Department Chair

Mr. McMahon is chairman of the firm and head of the firm’s Family Law Department. Mr. McMahon’s practice emphasizes civil litigation. He has tried in excess of 100 cases before juries, judges, arbitration panels and administrative law judges.

The more than 100 cases he has tried include matters in the disparate areas of anti-competitive practices, family law, construction, corporations, eminent domain, employment, insurance, intellectual property, limited liability companies, partnerships, personal injury, planning and zoning, products-liability, professional malpractice, real estate, and securities, among others.


Mr. McMahon received his B.S., cum laude, from the University of Southern California in 1956, and was awarded Order of the Palm as the outstanding graduating senior. He graduated summa cum laude from the University of San Diego School of Law in 1964, where he was the Notes Editor of the San Diego Law Review. While attending law school, Mr. McMahon was designated the St. Thomas More Scholar for the highest grade-point average in his class, and was named to the Order of the Coif.

Employment Background

Mr. McMahon was a naval aviator and, later, before entering the practice of law, held the position of Chief of Contracts for General Dynamics Corporation’s Centaur Space Vehicle Program.

Representative Matters

  • Represented manufacturer of medical device in patent infringement action against manufacturer of competing device
  • Defended international software maker against putative class action alleging defects in the software
  • Represented national fast-food chain in trade name infringement action
  • Represented national hospital corporation in defense of wrongful termination-of-employment action by several plaintiffs alleging dismissals in violation of public policy
  • Represented national chain of warehouse clubs in defense of anti-competitive practice claims by former supplier and in defense of a securities class action brought by shareholders
  • Defended law firm that had rendered tax opinion for a tax-shelter offering against investors’ claims
  • Represented developer of 340-unit condominium in defending against class action brought by homeowners
  • Represented religious leader before a jury of 550 of his peers
  • Represented building owner in construction-defects action against architect, general contractor and subcontractors
  • Represented national manufacturing corporation in defending class action brought by its California franchisees
  • Represented corporate majority shareholder in action against minority shareholder for usurpation of corporate opportunity
  • Represented spouse of principal in money management firm in dissolution-of-marriage proceeding
  • Arbitrated, before a tribunal of the International Court of Arbitration, royalty-sharing issues between holder of wireless telephone technology patent and an agency of a foreign government
  • Represented national trader of electric energy in putative class actions alleging unfair competition
  • Co-defense liaison counsel in coordinated California tobacco litigation proceedings
  • Represented several judges in individual matters

Professional Affiliations & Admissions

  • U.S. Supreme Court
  • California Supreme Court
  • U.S. Ninth Circuit Court of Appeals
  • U.S. District Court, Northern, Southern and Central Districts of California
  • U.S. Claims Court
  • Co-Chair, San Diego County Bar Association Conference on Diversity and Advocacy (1995)
  • University of San Diego School of Law (Chairman, Board of Visitors, 1980, 1996-1998)
  • Chairman, Drafting Committee, San Diego Civil Settlement and Trial Manual (1978)
  • Judge Pro Tem, San Diego Superior Court (1978 to date)
  • Member of the American Arbitration Association Panel of Arbitrators
  • Judicial Arbitrators Committee, San Diego Superior Court (Arbitrator and Member, 1979 to date)
  • Chairman, Drafting Committee, San Diego Civil Settlement and Trial Manual (1978)
  • California State Bar District No. 9 (Disciplinary Referee Pro Tem, 1976-1978)
  • Adjunct professor of law and Assistant Director, Staff of Trial Techniques Course, University of San Diego School of Law (1969-1972)
  • Barristers (Member, Board of Directors, 1969-1970)
  • American Inns of Court, Louis M. Welsh San Diego Chapter (Master Barrister)
  • San Diego Inns of Court, Inc.
  • San Diego County Bar Association (Vice President and Director, 1974-1977)
  • State Bar of California (Litigation and Family Law Sections)
  • American Judicature Society
  • Phi Alpha Delta Legal Fraternity

Community Affiliations

  • Sidney Kimmel Cancer Center (former Member, Board of Trustees)

Publications & Speaking Engagements

  • Panelist, San Diego Trial Lawyers Association Masters of Advocacy Seminars (1986, 1989, 1991)
  • Speaker, San Diego Trial Lawyers Association, “Keys to Victory at Trial (or Some Good Excuses if You Lose)” (1989)
  • Demonstrator, American Board of Trial Advocates/San Diego County Bar Association seminar “Trial of a Sexual Harassment Case” (1992)
  • Demonstrator, State Bar of California Convention, “Comparative Cross Examination” (1993)
  • Demonstrator, U.S. Department of Justice United States Attorney’s Advocacy Institute, “Cross-Examination” (1994)
  • Speaker, The Rutter Group, “Punitive Damages, Preparation & Trial” (1996)
  • Panelist, California Continuing Education of the Bar program, “Creating and Implementing a Discovery Plan”
  • Panelist, California Continuing Education of the Bar program, “Effective Civil Discovery”
  • Panelist, California Continuing Education of the Bar program, “How to Make the Law of Evidence Work for You”
  • Panelist, California Continuing Education of the Bar program, “Effective Law and Motion Practice”
  • Panelist, California Continuing Education of the Bar program, “How to Prepare for Trial”
  • Panelist, California Continuing Education of the Bar program, “Effective Jury Voir Dire”
  • Panelist, California Association of Business Trial Lawyers Seminar (2001)
  • Founding Director, lecturer, demonstrator and workshop leader for San Diego Inns of Court, an Institute of Trial Advocacy
  • Lecturer at California Western Law School on the use of expert witnesses and the art of taking a deposition

Professional Awards & Honors

  • Fellow, American College of Trial Lawyers
  • The American Academy of Matrimonial Lawyers
  • Designated as Distinguished Alumnus, University of San Diego School of Law (1976 and 1980)
  • American Board of Trial Advocates, San Diego Chapter (President, 1981)
  • Recipient of Daniel T. Broderick, III Memorial Award, bestowed by representatives of the San Diego Plaintiffs’ Lawyers Association, Defense Counsel Association and Bar Association, upon “an attorney with substantial litigation experience who epitomizes the principles of civility, integrity and professionalism” (1991)
  • Best Lawyers in America in Business Litigation, Family Law and “Bet-the-Company” Litigation categories (1988-current)
  • Named as one of three lawyers for 2010 in Southern California, based upon their particularly high level of peer recognition
  • University of San Diego School of Law, 2010 Hughes Career Achievement Award
  • San Diego Super Lawyers – 2014, 2015 (Business Litigation)
  • Named as one of the "10 Best" Attorneys in California by the American Institute of Family Law Attorneys (2015)