Background: Dunne, 60, of Kings Park, is running on the Republican, Conservative and Reform party lines in the general election. In January 2017, he was appointed acting County Court judge to handle felonies. He was a judge on the Suffolk County District Court from 2012 to 2016. From 2002 to 2012, he worked at the Suffolk County Department of Law, assigned to the Federal Torts Bureau. His responsibilities there have been to defend members of the Suffolk County Police Department, Sheriff's Department, and correction officers in federal court when they are sued while discharging their duties. From 1986 to 2002, he was assistant district attorney in the Suffolk County district attorney's office. There he prosecuted several long-term investigations, rackets cases, homicide cases and major crime cases. He received his undergraduate degree from the State University of New York at Albany in 1980, his masters from New York University in 1982 and his law degree from Touro College School of Law in 1986. He was admitted to the New York State Bar in 1987. Dunne is a member of the Suffolk County Bar Association. He is a member and former director of the Suffolk County Criminal Bar Association.

Background: Hennings, 57, of St. James, is running on the Republican, Conservative and Reform party lines in the general election. He has been a law clerk for State Supreme Court Justice Linda Kevins since January. Hennings was a part-time assistant counsel to State Sen. John J. Flanagan from May 2015 to 2017. He was a practicing attorney at Lawrence, Worden, Rainis & Bard from 2008 to 2017. Before that, Hennings worked at Devitt, Spellman and Barrett from 2005 to 2008. He worked at the law office of Ted M. Tobias from 1996 to 2005, and at Wortman Fumuso from 1989 to 1996. Hennings was an assistant district attorney for the Suffolk County district attorney's office from 1986 to 1989. He has worked as an attorney for the Smithtown Board of Zoning Appeals since 2012. Hennings received his bachelor's degree from Providence College in 1983 and his law degree from The Columbus School of Law at The Catholic University of America in 1986. He was admitted to the New York State Bar in 1987 and to the U.S. District Courts, Eastern and Southern Districts, in 1989. He is a member of the New York State Bar Association and the Suffolk County Bar Association.

Background: Holst, 66, of Nesconset, is running on the Democratic, Green, Working Families, Independence and Women's Equality party lines in the general election. He is currently in private practice after serving 13 years as an assistant county attorney in Central Islip. Holst was corporation counsel to the City of Long Beach from March 2002 to January 2004. He was elected to the Suffolk County Legislature in 1997. He was appointed as Suffolk County clerk in 1989 by then-Gov. Mario Cuomo, and March 1988 to May 1989, served as deputy commissioner for consumer affairs under former Suffolk County Executive Patrick Halpin. Holst was an assistant Smithtown town attorney from 1987 to March 1988. He is currently a member of the Smithtown Anti-Bias Task Force. He graduated from New York University in 1974 and got his law degree from St. John's School of Law in 1982. He was admitted to the New York State Bar in 1983. He was admitted to the U.S. District Courts, Eastern and Southern Districts, in 1983. Holst belongs to the New York State Bar Association and the Suffolk County Bar Association. He served in the U.S. Army from 1975 to 1978.

Background: Rosenthal, 61, of Hauppauge, is running on the Democratic, Green, Working Families, Independence and Women's Equality party lines in the general election.  An assistant county attorney since May 1986 at the Suffolk County Attorney's Office, he is in the Family Court/Social Services Bureau. His duties include prosecution of child abuse and neglect cases for Child Protective Services, termination of parental rights cases for children in extended foster care to free them for adoption, and prosecution of juvenile delinquents.  In 1985-1986, Rosenthal worked for the Legal Aid Society of Suffolk County as a staff attorney in the Law Guardian Bureau. He graduated in 1979 from C.W. Post Campus of Long Island University, now known as LIU Post, and received his law degree in 1983 from Memphis State University, now the University of Memphis. He was admitted to the bar in 1985. He is a member of the Suffolk County Bar Association and a mentor to law students in the summer intern program at Suffolk County Family Court. He received the Champion for Children Award from Parents for Megan's Law in 2005, and the Child Abuse and Neglect Professional of the Year Award from the Suffolk County Advisory Committee on Child Protection in 1993.