Castle Wiki
John Knox
Wikia Castle - John Knox
John Knox at his ease in the interrogation room
Vital Statistics
Gender Male
Status Deceased
Cause of death Multiple gun shot wounds
Character Information
Appearances "Love Me Dead"
Portrayed by Jonathan LaPaglia

John Knox was the truly scary combination of muscle and brains, a leg-breaker who could extemporise on why he was removing someone's kneecaps.

Knox was a career criminal with practically no rap sheet, which declared both his brains and his luck, and when Beckett and Castle met him in "Love Me Dead", he was their prime suspect for the murder of Assistant DA Jack Buckley. After all, Buckley had dragged Knox down to his office, and they'd been heard yelling at each other. Yet from the moment he sat, or rather dropped, in the chair in the interrogation room, the duo knew something wasn't right. Knox made it seem like they were guests in his home, rather than him being the press-ganged visitor to the station. It turns out Knox was at an AA meeting when Buckley was killed, with his sponsor, who's a priest. Dead end.

Or maybe (K)not. Through various twists and turns, and the defrocking of DAs and priests alike, it emerges that Buckley was the organizer of a call girl ring, and Knox wasn't at his AA meeting. One of the call girls had embarrassing photos of the priest, and he was being blackmailed to provide the alibi. The call girl, Scarlett Price, turned to Beckett and, especially, Castle for help and protection, and they rescued her just as Knox was about to tie up loose ends.

And again, the tables revolve. Scarlett, in fact, set up the fake kidnapping to hide her own killing of Knox, who had been her partner in taking the ring away from Buckley, but had since become a liability. Knox was double-crossed, just as he had done to Buckley.