Career
He is a widely cited author. He has published multiple works on the intersection of international law and counter-terrorism. Murphy spent the year following earning his law degree participating in Syracuse University's Afro-Asia Public Service Fellowship Program working in India with the Indian government.
Upon his return he spent a year working on Wall Street. He then spent 1964-1967 in the United States State Department's Office of the Legal Advisor. He returned to private practice from 1967 to 1969.
In 1969 he took a teaching position at the University of Kansas School of Law. Since then he has taught at Cornell University, Georgetown University, the Naval War College and finally Villanova, in the United States. Outside the USA he has taught in Aix-en-Provence, London, Mexico City, Paris and Haifa.
Murphy has held positions of trust within professional organizations. He served on the Executive Council of the American Society of International Law and on the Society's Board of Review and Development. He was an honorary Vice President of the American Branch of the International Law Association.
He served as a consultant to a number of organizations, including the State Department, the United States Department of Justice, the United Nations Crime Prevention Unit and the International Task Force on Prevention of Nuclear Terrorism. He has served on the editorial boards of a number of legal journals. In 2010 Murphy's employer, Villanova University, held a symposium to honor his forty year tenure as a legal scholar.