Believing that all police work should be by-the-book, Jake McCarthy seems an unlikely choice of partner to the rather reckless Sara; nevertheless, after the death of Sara's previous partner, Jake and Sara were assigned to the Microwave Murders.

Often naive, but always determined, Jake has often suffered for his work; he has been hospitalised by Kenneth Irons, Bruce Wilder and Ian Nottingham... a victim to the pain that Sara can so easily avoid thanks to the regenerative powers of the 'blade. Jake holds a personal vendetta against Gavin Taylor since the man killed Jake's ex-fiancee, Cynthia.

Sara recently healed Jake with the Witchblade, commanding it to 'make him stronger'; quite what it has done is unknown, although Jake now seems far more confident, even to the extent of Sara finally telling him about the Witchblade itself.