McDonald, 61, of Garden City, is running on the Democratic and Republican party lines. He has been a partner at the law firm of Collins, McDonald & Gann in Mineola since 1990. Before that, McDonald worked as an assistant district attorney for Nassau County from January 1984 to November 1989. He attended New York University, graduating in 1977 with a bachelor's degree in dramatic literature with a minor in politics. He received his law degree from St. John's University in 1983. McDonald was admitted to the New York State Bar in 1984 and the Eastern and Southern District of New York Federal District Court in 1985. McDonald is a member of the New York State Bar Association and the Nassau County Bar Association, where he served as a member of the Grievance Committee. He is also a member of the Criminal Courts Bar Association and the Former Assistant District Attorneys Association. McDonald has been a special professor of law at Hofstra Law School since 1998, where he has coached the mock trial teams, taught a prosecutor's class and worked as a lecturer for the National Institute for Trial Advocacy.