In early 2258, he investigated the remains of a freighter destroyed by Raiders with Michael Garibaldi. Shortly after, he served as Commander Jeffrey Sinclair's wingman when he led Delta Wing to intercept another Raider attack. After driving off the Raiders, John and Delta Nine escorted Sinclair while he searched a nearby asteroid field, finding the Raider's command and control ship. 
Months later, John and the rest of Delta Wing, under the command of Lieutenant Commander Susan Ivanova, scrambled in response to an apparent Raider attack on a freighter. They were recalled once it was realized the attack was a diversion intended to weaken Babylon 5's defenses as a prelude to an attack on the station. Delta Wing returned as the attack was in progress, just in time to complete a pincer maneuver the Raiders' fighter force. 
Shortly after his thirtieth birthday, John had been reassigned to Alpha Wing. He was sent to investigate a disturbance in Sector 14, the location where Babylon 4 disappeared. A tachyon pulse from the temporal rift opening caused his internal organs to triple in age. He managed to set the auto pilot to return to Babylon 5, and scratched "B4" into his seat buckle before dying of "natural causes." 
- The name "John" is legible on the patch on the left breast of his flight suit in "Signs and Portents" and "Babylon Squared." His surname is obscured by his restraints.