Francis D. Murnaghan, Jr. was born in Baltimore on June 20, 1920. Murnaghan graduated from Baltimore City College in 1937 and went on to college at Harvard. After his freshman year he transferred to Johns Hopkins from which he graduated. While at Hopkins Murnaghan played on a national championship winning lacrosse team and graduated Phi Beta Kappa with honors in 1941.

After his graduation, Murnaghan enlisted in the United States Navy and was assigned to a classified intelligence unit tasked with cracking Japanese codes, despite his preference for being placed in active duty. His brief military career was illustrious. Murnaghan was promoted to the rank of a commissioned officer and decorated several times.

His uncle, James Murnaghan, an Irish Supreme Court Justice, was a strong influence on his life and encouraged his interests in art and law. After World War II, Murnaghan entered Harvard Law School, graduating in 1948. His first position post-law school position was as an associate with the Philadelphia law firm of Barnes, Dechart, Price, Smith and Clark. In 1949 he married Jane Hughes. After two years he left to work for Robert Bowie, the General Counsel to John J. McCloy, the High Commissioner of the American Zone in Germany where he was a member of a team who administered the I.G. Farben Company.

Murnaghan became an associate at Venable, Baetjer, and Howard in1952 but took an immediate leave of absence to become Assistant Attorney General for the State of Maryland Comptroller's Office. Murnaghan returned to Venable, Baetjer & Howard in 1954. While at the firm he specialized in litigation and became a legal expert in libel and slander. In 1957 he was made a partner and remained at Venable, Baejter, & Howard for 22 years.

Murnaghan was also active in the local civic community during this time. He chaired the Baltimore Charter Revision Commission in 1963 and 1964 and also served as president of the Baltimore School Board from 1967 to 1970. Judge Murnaghan had a passion for art and collected Irish art. He was a trustee of the Walters Art Gallery, the Peabody Institute, and the Johns Hopkins University.

Francis Murnaghan, Jr. was a leading member of the Maryland Democratic Party. He chaired Senator Paul Sarbanes Senate election campaign in 1976 and Governor Harry Hughes vice- chairman in his first campaign for the governorship. In 1979 President Jimmy Carter appointed Murnaghan to the United States Court of Appeals of the Fourth Circuit. As a federal court of appeals judge, Judge Murnaghan was politically liberal-leaning and was often a dissenting voice on the court.

In 1984, divorced from Jane Hughes since 1972, Judge Murnaghan married Diana Lee Edwards. Judge Murnaghan died in 2000.