Although he has a slightly shy personality for a soldier, Murphy has a fierce past where, in order to retaliate against a street gang for mercilessly murdering his brother, he shot 20 members of the organization one after another with a hunting rifle. His god-like sniper skills, referred to as first-class in the Marine Corps, caught the eye of a coordinator who rescued him from serving life imprisonment, and he joined the U.B.C.S.
The player encounters an injured Murphy in Umbrella's sales office and the way his death is played out changes depending on how the player handled their previous battle with Nemesis. In one version of the scene, since he drank T-Virus contaminated water following the U.B.C.S. unit's annihilation in Raccoon City, he faces his best friend Carlos Oliveira and begs him to shoot him, in which Carlos reluctantly complies. In another version, Nicholai Ginovaef shoots him, even though he can be heard pleading for his life.
- Murphy was twenty-seven at the time of his death, according to BIOHAZARD 3 LAST ESCAPE Official Guidebook - Complete Conquest of Nemesis.
- Murphy is absent from S.D. Perry's novelization, instead replaced by an original character named Randy Thomas.