Judge Fitzsimmons was appointed United States Magistrate Judge for the District of Connecticut on June 4, 1993. She is a 1971 magna cum laude graduate of Smith College, where she majored in history and was elected to Phi Beta Kappa. In 1976, she received her J.D. and an M.A. in legal history from the University of Virginia, where she and her partner won the Lile Moot Court competition. Before becoming a lawyer, she was a newspaper reporter.
Judge Fitzsimmons joined the U.S. Attorney's Office for the District of Connecticut in 1978 after two years at the firm of Robinson & Cole in Hartford. At the U.S. Attorney's Office, she was an Assistant U.S. Attorney in the Criminal Division (1978-1982), Lead Attorney for the New England Organized Crime Drug Enforcement Task Force in Connecticut (1982-1986), Assistant-in-Charge of the Bridgeport Office (1986-1989), and Chief of Special Prosecutions and Senior Litigation Counsel (1989-1993).
Judge Fitzsimmons is president of the Raymond Baldwin Inn of Court and serves on the Judicial Conference Committee on Financial Disclosure and the Second Circuit Committee on History and Commemorative Events. She is a member of the Federal Magistrate Judges Association, and was a founding member of the Hartford Association of Women Attorneys. As editor of the Bulletin of the Federal Magistrate Judges Association, she attends meetings of the Magistrate Judges' Advisory Committee for the U.S. Courts.
She has taught trial practice at Yale Law School since 1992.