Ensign Murphy was Starfleet security officer serving aboard the USS Voyager under Captain Kathryn Janeway. Murphy was stranded in the Delta Quadrant when the Voyager was forcibly brought there by the Caretaker in 2371.
In 2373, Murphy was ordered by Chakotay, to escort the Ferengi Arridor and Kol to secured quarters. The Ferengi, however, were able to knock Murphy unconscious and were able to escape, leaving Murphy with a concussion. (VOY: "False Profits")
Murphy was played by regular background actor Shepard Ross who received no credit for his appearances. This Murphy is different than the Ensign Murphy who served in the science division on board Voyager. The Star Trek Customizable Card Game gives his name as Andreas Colter.