Doctor Morley was one of three resident doctors at the San Cristobal Medical Facility aboard Sevastopol Station, along with Dr. Lingard and Dr. Kuhlman. When a lone Xenomorph was unleashed on the station by the crew of the Anesidora in 2137, he became one of the survivors desperately waiting for rescue.
Morley was attacked and killed by the Xenomorph in San Cristobal.
At some point during the Xenomorph infestation on Sevastopol, Morley was ambushed by the Xenomorph in San Cristobal. The creature brutally eviscerated him before tearing a hole through his face, killing him. Amanda Ripley later stumbled upon Morley's mutilated, disfigured corpse whilst exploring San Cristobal in search of his keycard.