David has been practicing law for over 30 years, representing clients in a wide variety of matters including civil litigation, personal injury, workers' compensation, medical malpractice, criminal, serious traffic offenses, consumer bankruptcy, collections, estate planning and estate administration, and business planning and transactions.

David earned a Bachelors of Arts in Philosophy from Saint Michaels College in 1980, and earned his Juris Doctor from The New England School of Law in Boston, Massachusetts in 1983. After building his practice in Baltimore, he associated with his late partner, Bruce Ezrine, in 1987, practicing as Ezrine and Castro until 1997. He has been honored to practice law with Jeffrey Stavisky since 1991.

David was admitted to the Maryland Bar in 1983 and regularly represents clients in the Maryland State District, Circuit, and Appellate Courts, as well as in the United States District Court for Maryland and the United States Bankruptcy Court for Maryland. He is a member of the Maryland State Bar Association and the Maryland Association for Justice (formerly the Maryland Trial Lawyers Association).