Background: Fairgrieve, 67, of Mineola, is running on the Democratic, Working Family, Independent, Women's Equality, and Reform party lines in the general election. He has been  a Nassau County District Court judge since 2001, an adjunct professor at LIU Post teaching business law since 2005, and an acting county judge since 2010. Fairgrieve was a Mineola Village trustee from 1982 to 1994, appointed deputy mayor of Mineola Village from 1985 to 1987. He received his undergraduate degree from Adelphi University in 1973 and graduated from St. John's University Law School in 1976. Fairgrieve was admitted to the New York State Bar in 1977. He is a member of the Nassau County Bar Association.

Background: Mastroianni, 62, of Westbury, is running on the Republican and Conservative party line in the general election. She is serving as a support magistrate for Nassau County Family Court since 2015, specializing in child support and paternity cases. Mastroianni was a partner at Mastroianni & Mastroianni, Esqs., from 1988 to 2015 and an attorney for Children Panel from 1999 to 2015. She received her undergraduate degree from Adelphi University in 1978 and graduated from Hofstra University School of Law in 1987. Mastroianni was admitted to the New York State Bar in 1988 and the U.S. District Court, Eastern District of New York Bar, in 1992. She is a board member for the Nassau County Women's Bar Association and a member of the New York State Bar Association, the Nassau County Bar Association and the New York Family Law American Inn of Court. Mastroianni served as the president of the Nassau County Columbian Lawyers Association in 2017.