He owns and his company manages numerous commercial and residential properties. He has been an expert witness in real estate cases, acts as a mediator and arbitrator and has presented at real estate seminars to attorneys, brokers and real estate professionals. Gerro has also published several articles in such publications as Los Angeles Lawyer magazine, Real Property News, the State Bar Journal and Business Life. He has served in leadership roles for a number of organizations and boards, including the Association of Real Estate Attorneys, Themis Society, the Burbank Bar Association and the Lawyers Association of Los Angeles. He is the former chairperson for the Real Property Section, Finance Subsection, Los Angeles County Bar Association and for the Burbank Chamber of Commerce, Development Committee.