“After a courageous and arduous battle with cancer,” John writes in the Sunday letter, “I have been informed by my doctors that all treatment options have been exhausted, and I now face a terminal diagnosis.”

John, 85, won his fifth term in November. The longtime public official said he made the decision “with the intention of focusing on my health and spending cherished time with my family during this challenging period.”

A lawyer by trade, John before coming to the Legislature previously was a judge in Superior Court and District Court; state Court of Appeals justice; and directed the crime lab of the State Bureau of Investigation.

He was first elected to a seat on Jones Street in 2016.

Rep. Robert Reives, the Democratic leader of the House, in a statement thanked him for public service and said, “Our caucus and our state are lucky to have him.”

John has represented a northwestern part of the county in District 40. The county’s Democratic Party will choose his successor.