Upon co-founding his firm in January 2016, Larson was quickly tapped that February to file a legal brief supporting the U.S. government's efforts to force Apple Inc. to unlock the encrypted iPhone belonging to one of the shooters in the 2015 San Bernardino attack. Soon after, he was hired to serve as interim general counsel for the Ontario International Airport Authority during the time that it was finalizing its separation from Los Angeles World Airports. Larson was also appointed by the Orange County District Attorney and the Orange County Board of Supervisors to monitor the District Attorney’s compliance with a Blue Ribbon commission’s recommendations related to jail informants.