Haddam was born in Bethel, Connecticut and lived in Watertown.[4][5][6] She was married to mystery writer William L. DeAndrea until his death in 1996.[4] One of their two sons, Matt DeAndrea, is also a writer; the second is named Gregory DeAndrea.
Papazoglou worked as a teacher at the college level and as a magazine editor.[7] She began her fiction writing career after attending the 1981 Romantic Times Booklovers' Convention, which she was covering as a journalist. After her article about the conference was rejected, Papazoglou sat down and began to write the first Patience McKenna novel, Sweet, Savage Death.[8] She would eventually write five McKenna novels, under her real name, between 1984 and 1990.
Between 1983 and 1988, Papazoglou wrote six romance novels. Four were published under the name Nicola Andrews for Jove's Second Chance at Love line, and two were published by Pocket Books under the name Ann Paris.[8]
She was best known for her series of mysteries written as Jane Haddam featuring Gregor Demarkian, a former FBI agent.
Haddam was nominated for an Edgar Award in the "Best First Mystery Novel by an American Author" category for her novel Sweet, Savage Death in 1985.[9] Her novel Not a Creature Was Stirring also received an Edgar nomination, this time for "Best Paperback Original";[10] it was also nominated for the 1991 Anthony Award in the same category.[11]