Though a normal military surgeon, Knox was one of the doctors ordered into Ishval as pathologists to gather information on the effect of burns and pain on the human body by using Ishvalans as test subjects. He became very acquainted with the Flame Alchemist's style as the expert assigned to dissect the bodies of Ishvalans that Roy had killed. He continued practicing pathology and forensics after the war, feeling that he had lost the right to treat living people. Even after returning from the battlefield, Knox began suffering from post-traumatic stress disorder in the form of flashbacks, insomnia and nightmares of Ishval.

He has an ex-wife and a grown son.