Presumably Agent Johnson grew up in the New Chicago metropolitan area before the Total War. Following the Total War, he received the Mark and soon began working at DOME’s Umbrella center in Spokie. When his department became aware of Peck’s activities, Agent Johnson and the other agents attempted to locate him. Unable to learn Peck’s identity, they tried to destroy his support system, killing Peck’s friend Jon and leaving another friend, Trenton, with severe brain damage. These efforts were ultimately unsuccessful in reaching the real object of DOME’s efforts—arresting Peck.
“There was a visitor on the day our equipment went missing… She just happened to have clearance.” —Agent Johnson
When Charles Arbitor arrives in Spokie to hunt down Peck, Johnson is one of the agents assigned to his team. Charles, Johnson, and the other agents find themselves at a loss in their attempts to solve the case. Soon they have another problem on their hands—a mysterious vigilante who stole surveillance equipment from DOME and used it to track Peck on his or her own. Johnson is the one who ultimately puts together the various strands of evidence after an anonymous tip warns about the Dust’s plan to kidnap Dane Harold at a Battle of the Bands that evening. Charles's daughter Erin, Johnson explains, used her family privileges to enter the Umbrella building and steal the equipment. She is accompanying the anonymous caller to the concert, thereby putting herself in serious danger.
Charles, Johnson, and the team of DOME agents go to the concert, hoping to catch the Dust and confront Erin about her vigilante activities. Johnson helps find Erin and Logan Langly at the concert, and Charles orders him to magnecuff them when one of Erin’s comments angers her father. Just as Johnson is about to cuff them, Logan throws flash pellets on the ground. Johnson, like the other agents, is briefly blinded, and Logan and Erin escape. Once the DOME team has gotten its sight back, they rush to the Fulmart, where they fail, again, to catch the Dust. They arrest Logan and Erin and return to the Umbrella.
When Erin tells DOME the location of Peck’s warehouse, Johnson is among the agents who raid the warehouse and follow the fleeing Dust. This attempt, like the others, is unsuccessful.
“You remember where we left off?”
“I do remember. We had just finished the part where you didn’t listen to anything I had to say, and, if memory serves, we were about to begin…oh, that’s right! Wasting my time.”
— Agent Johnson and Erin Arbitor
Agent Johnson is the one who was assigned to interrogate Erin about her involvement in Logan Langly’s escape. Evidently he questioned her about hacking into the Center, but his suspicions made no headway against Erin's sarcasm. By the time he talks to Erin in Sneak, he has come to realize that Erin—although probably guilty—will never confess to the hack. Instead, Johnson enlists Erin’s help in finding Logan. While Erin does manage to help the DOME agents locate her friend, the agents bungle the affair again. Presumably Johnson participated in the raid on the Hayes’s farm, although exactly what part he played is unknown. Following Peck’s flight to Beacon City and Charles Arbitor’s transfer, Johnson and the other agents return to their regular duties.
Johnson is generally a considerate person, striving to tell Charles Arbitor of Erin’s vigilantism very gently. He also avoids directly accusing Erin of engineering Logan’s escape. Johnson has a keen analytical mind, however, and executes missions as well as any of the other DOME agents. Unfortunately for DOME, even its best agents don’t execute missions well enough to capture Peck.