Romerio was a member of the United States Colonial Marine Corps from the USS Sephora. Romerio was one of the Marines caught in an internal explosion aboard the USS Sulaco that occurred just as Corporal Christopher Winter was attempting to board the Sulaco from the Sephora via the umbilical. Although he survived the explosion aboard the Sulaco (with injuries) Romerio's fate afterwards is unknown but it is likely he was captured and taken to a Hive by Xenomorphs aboard the Sulaco as he was nowhere to be found when Cpl. Winter and Keyes returned to the hangar with the flight recorder.
Romerio was one of the Marines sent aboard the USS Sulaco to investigate the ship. Romerio was one of the several Marines injured in the internal explosion aboard the Sulaco that occurred just as Cpl. Winter was attempting to board the ship via the umbilical from the USS Sephora. Romerio was being helped by Private Peter O'Neal and Paluski when Cpl. Winter boarded the Sulaco.
When Winter and Keyes returned, Romerio and the other injured Marines were nowhere to be seen, presumably having been captured by the Xenomorphs and taken to one of the Hives on board the Sulaco.