Harold C. Trimmer


Harold Trimmer’s practice focuses on professional liability, general civil litigation, as well as white-collar criminal defense and related matters.

Mr. Trimmer represents professionals and businesses in civil, criminal, and administrative proceedings. On the civil side, he has defended law firms, lawyers, real estate professionals, and accountants in civil malpractice actions. He has also represented businesses and individuals in a variety of other disputes, including embezzlement investigations and litigation, theft of intellectual property, contract disputes, fraud matters, and other business disputes. He has also authored and argued appeals before the California Court of Appeal and the Ninth Circuit.

Mr. Trimmer is also experienced in representing individuals in state and federal criminal actions, as well as, quasi-criminal administrative investigations, including embezzlement, political corruption investigations, real estate fraud, military procurement fraud, investment fraud, SNAP fraud, medical billing investigations, bankruptcy fraud, and other complex criminal matters. Mr. Trimmer has also defended real estate professionals, nurses, veterinarians, and doctors in professional licensing matters, including successfully authoring and arguing writs of mandamus to reverse a board’s decision to revoke a license.

A native of Las Vegas, Mr. Trimmer graduated from Georgetown University’s Edmund A. Walsh School of Foreign Service with a bachelor of science in foreign service in 2002. In 2006, he received his J.D. from the University of San Diego, School of Law. During his undergraduate studies, he researched international trade policy at the Center for Strategic and International Studies and was a policy advisor on e-commerce issues at the Office of the United States Trade Representative. Prior to attending law school, he was the marketing director for a Santa Barbara internet startup.

Prior to joining Klinedinst, Mr. Trimmer was an associate in a boutique civil and criminal litigation firm in San Diego. In 2013, he was named one of San Diego’s Top Young Attorneys by The Daily Transcript. He is active in the San Diego Defense Lawyers and an alumnus of the Louis M. Welsh Inn of Court.



San Diego
(619) 400-8000


Harold C. Trimmer, Esq.


  • California (2006)
  • U.S. District Court, Southern District of California (2006)
  • Ninth Circuit Court of Appeals (2013)
  • U.S. District Court, Central District of California (2014)