Wooley, 23, of Guntown, Mass, and Castromata, 19, of Oakley, Calif., were shot to death by Sgt. Eusebio Lopez, 25, of Pacifica, Calif., a spokesman for the Marine base said in a statement.
Lopez seized Castromata and shot her and later himself Thursday inside Taylor Hall, a barracks for members of the Officers Candidate School. Lopez also shot Wooley, though it was not reported if that occurred before or after he shot Castromata.
The incident is being investigated by the Navy Criminal Investigative Service, The Washington Post reported.
All three of the dead knew each other. An officer who didn't want his name used told The Washington Post investigators are trying to determine the motive for the violence, including the possibility of a romantic relationship.
The base is "still unable to answer many questions," the release said.