We first meet Jimmy Knight when Strike attends a CORE meeting in an attempt to find Jimmy’s younger brother, Billy. (CORE is an activist group organized by Jimmy that is protesting the Olympics.) Jimmy describes CORE as “part of a broader global justice movement that meets repression with resistance.” In addition to CORE, Jimmy also runs the Real Socialist Party that his girlfriend, Flick, describes as “the real spirit of the Labor movement.” Both organizations have websites that list lengthy schedules of events where Jimmy is set to speak or protest. Jimmy is “very keen on his rights” and has brought so many civil actions against individuals and organizations that he is now “forbidden from starting civil cases in courts without permission.”

During his initial meeting with Jasper Chiswell, the Minister tells Strike that Jimmy Knight is one of the two people who are blackmailing him. Chiswell tells Strike that “Jimmy Knight is aware that I did something that I would not wish to be shared.” While insisting that his actions were not illegal, Chiswell explains that Knight has demanded “forty thousand pounds in hush money.”

Jimmy grew up on the Chiswell house grounds with his abusive and alcoholic father and his younger brother, Billy. Jimmy explains that his mother died due to asbestos when Billy was two. 

Strike meets and interviews a woman called Dawn Clancy who was previously married to Jimmy Knight. Dawn tells Strike that Jimmy had a lot of girlfriends on the side who saw him as some sort of “pop star.” She also talked about his many civil suits and informed Strike that Jimmy is anti-Semitic.    

Strike has Barclay go undercover as an ex-army man who “didnae know whut he was gettin’ himself intae.” Barclay keeps tabs on Jimmy and Flick throughout Lethal White and keeps Strike and Robin informed on anything that could be connected to the Chiswell case. 

Jimmy is in his mid-thirties with dark hair and pale skin. With his political affiliations, he often hangs out with a crowd that is a good ten years younger than he is. Strike notes that Jimmy is “charismatic, articulate, good-looking, a chancer and a hothead.” Strike reflects that Jimmy’s “personality filled the room,” and he reminds Strike of the type of men his mother would have taken as a lover.

In the Lethal White TV series, Jimmy Knight is portrayed by actor Nick Blood.