Intro
David focuses his practice on public agency litigation with an emphasis on complex matters, class actions, and multi-party litigation. With a background in writs, appeals, and law and motion, David brings invaluable knowledge and a unique perspective to his cases. In state court, David is experienced with the California Government Claims Act and the array of defenses it provides to public agencies. In federal court, David routinely defends special districts, counties, and state departments against various constitutional claims.
David was a prior Summer Associate at Hanson Bridgett and a judicial extern for Chief Judge Jennifer Gee in the U.S. Department of Labor's Office of Administrative Law Judges. Currently, he is on the faculty at the University of California College of the Law, San Francisco (formerly UC Hastings) where he teaches legal research and writing, and appellate advocacy courses.
Areas of Focus
Education
Academic Distinction
Governor, UC Hastings Alumni Association Board of Governors
Member, UC Hastings Honor Society
Co-Chair, UC Hastings Moot Court Board (2017-2018)
Admissions and Courts
Role
Pro Bono Committee, Member
Recruiting Committee, Member
Public Transportation Law. Successfully represented local transportation districts in their defense against a high-stakes, multi-million dollar, class action alleging violations of state and federal due process clauses based on toll violation noticing procedures.
Government Law. Successfully defended local transportation district against putative class action alleging that toll invoices and penalties were unconstitutional fines.
Constitutional Law. Represented a group of business associations as amici curiae in appeal addressing injunctions on anti-camping ordinances across the American West under the Eighth Amendment.
Constitutional Law. Represented a group of behavioral science and economics scholars as amici curiae in appeal addressing interplay between free speech and equal protection rights.
Cannabis Law. Successfully defended a cannabis distribution company in a jury trial against a cannabis cultivator alleging distributor breached an implied-in-fact contract when distributor attempted to return unsellable cannabis and cannabis products.
Immigration Law. Secured a published Ninth Circuit victory on behalf of a gay Nigerian man seeking asylum and protection under the Convention Against Torture in the United States after he was discovered being intimate with his boyfriend in a Nigerian hotel and was threatened with death as a result of that discovery.
Hispanic National Bar Association, Regional Governor (Northern California & Hawaii) (2024-2025)
Hispanic National Bar Association, Chair of the Young Lawyers Division (2023-2024)
Leadership Council on Legal Diversity (LCLD), Pathfinder (2023)
Executive Committee of the Bar Association of San Francisco's Appellate Law Section
Bay Area Lawyers for Individual Freedom (BALIF)
The Barristers Club of the Bar Association of San Francisco
San Francisco La Raza Lawyers Association
The National LGBT Bar Association
"Hanson Bridgett's Brian Schnarr and David Casarrubias Featured on 2023 Lawdragon 500 X – The Next Generation," (July 2023)
"Meet UC Hastings Board of Governors Member David Casarrubias ’18," UC Hastings (August 2022)
"LGBTQ Attys and Staff Talk Inclusivity In Mid-Law," Law360 Pulse (June 2022)
"9th Circ. Says BIA Must Rethink Gay Nigerian's Torture Claim," Law360 (May 2022)
Lawdragon 500 X - The Next Generation, Appellate; Commercial Litigation (2023 – 2025)
California Lawyers Association, Wiley W. Manuel Pro Bono Legal Services Award (2018 – 2024)
Super Lawyers, Appellate; Civil Litigation (2023 & 2024)
Atlas Award Winner, 2023 LCLD Pathfinder Program
Judicial Apprentice to the Hon. Judge Judith L. Meyer, Los Angeles County Superior Court, Long Beach Courthouse
Judicial Extern to the District Chief Judge Jennifer Gee, U.S. Department of Labor, Office of Administrative Law Judges
"A California Court's Reminder On 'Law Of The Case' Doctrine," Law360 (September 2020)
"A Conversation with the California Latino Judges Association," moderator, HNBA Golden Bar Speaker Series (February 2025)
"Litigating Homelessness: Grants Pass and Other Recent Cases," panelist, UC Law’s Constitutional Quarterly (January 2025)
"Protect Frontline Workers: Safety Strategies, Rider Conduct, and Rule Enforcement (S)," co-presenter, California Transit Association Fall Conference (November 2024)
“Panel III: Lunch and Views from the Supreme Court with Associate Justice Evans,” Bar Association San Francisco (November 2024)
“Unhoused/Homelessness Presentation,” Commercial Real Estate Network (“CRePN”) (August 2024)
"Building Your Book of Business," Hispanic National Bar Association Annual Conference (September 2024)
"What's Next for Homelessness After Johnson v. Grants Pass?," Bay Area Council (July 2024)
"Current Court Cases on ADA," APTA 2024 Legal Affairs Seminar (February 2024)
"Personally Identifiable Information - Transit Agency Obligations & Risks," APTA 2023 Legal Affairs Seminar (April 2023)
"Perfecting the Appeal: Preservation Jurisdiction & Prosecution," CLA Annual Meeting (September 2021)