Mario is a real estate transactional attorney who represents developers, builders, investors, lenders, and others involved in a wide range of commercial, industrial, residential, hotel, and resort projects. In 1987, he became the first Hispanic managing partner of a Top 50 Los Angeles County law firm and remains a senior member of the firm's Executive Committee today.
Mario's involvement in community activities is long and deep. He has served on the boards of directors of a wide range of legal services and other nonprofit organizations, including the Legal Aid Foundation of Los Angeles, where he served as President in 1995, Public Counsel, Santa Monica College Foundation, Dale Ride Internship for Achievement of Minority Scholars at Santa Monica College, and the UCLA Law School Dean's Advocates, UCLA Law Founders, and UCLA Foundation Board of Councilors. He is past President of the Century City Chamber of Commerce. He was the youngest President of the Board of Governors of the California Community Colleges at age 32 and was legal Co-chair of Rebuild LA after the Los Angeles riots in 1992.