David P. Mastagni is the founder and managing partner of Mastagni Holstedt, a Sacramento-based firm nationally recognized for its advocacy on behalf of labor unions and public safety professionals. A distinguished trial attorney, David has tried more than 100 jury trials and over 300 proceedings to verdict. He has participated in over 450 appellate cases, including matters before the U.S. Supreme Court.
Throughout his career, David has been a fierce advocate for the rights of workers, advising public and private labor unions on contract negotiations, grievances, and arbitration. In 2003, he secured the largest law enforcement binding arbitration award in the nation. His expertise has influenced public policy through testimony before the California Legislature and contributions to the drafting of critical labor and employment laws.
David is a respected lecturer for the Peace Officers’ Research Association of California (PORAC) and a longtime panel attorney for the PORAC Legal Defense Fund. He served in the U.S. Army National Guard during the Vietnam era and earned his J.D. from McGeorge School of Law, where he received the American Jurisprudence Award in Evidence and now serves on the Dean’s Council.
A San Juan Unified graduate, David’s legacy includes decades of leadership in protecting the rights of working people and elevating the legal profession.