|Portrayed by:||Austin Basis|
J.T. grew up with Vincent, Vincent's two older brothers, and Alex Salter. J.T. was the first and only person Vincent reached out to after he returned from Afghanistan as an artificial evolved human. Since then, J.T. has been hiding Vincent from the men who have been hunting him. At some point, J.T. and Vincent became roommates and research partners, as they work together to find a antidote to take away Vincent's abilities and to cure an affliction that turns him into a beast whenever he’s angry.
In 2012, much to J.T.'s dismay, Catherine found Vincent alive and hiding in their warehouse. However, he relaxed a little when it became clear that she would keep their secret. However, J.T. made it clear to Vincent that he still saw her as a danger to both of them. For all three of their sakes, J.T. would often try to discourage Vincent from having anything to do with Catherine and vice versa. However, his words of discouragement would often fall on deaf ears because Vincent and Catherine were both extremely protective of each other.
Anyway, his stand against Catherine being in their lives softens some what after he found out that her mother was involved in the experiment that turned Vincent into a beast, and after she helped him find an antidote for Vincent's blackout. Sometime later, Evan Marks approached him at the university and told him that he had read his paper on cross-species dna and would like his help in finding a cross-species creature living in new york.
J.T. likes to run jokes and is a very sarcastic person. However, he tends to speak a bit more sarcastically with Catherine than with anyone else. This is because his fear of Muirfield finding him and Vincent and his own overprotective nature often pits him against Catherine, who he sees as a danger to himself and Vincent.
J.T. is tall and chubby, with pale skin, and brown hair. He always dresses casually even when he is at work. J.T. also wears prescription glasses.
J.T. grew up with Vincent and was his room mate when they both attended medical school. When Vincent returned from Afghanistan, J.T. was the person he turned to for help. In Saturn Returns, J.T. tells of how he attempted to live a double life initially, helping Vincent in secret whilst maintaining a normal life with his girlfriend, but eventually it became too hard due to having to constantly lie to those around him. They both now live in an abandoned warehouse which they have furnished to make habitable. It is clear that he cares a lot about Vincent. He is very protective of him, lying about his existence to Catherine and Tess when they come to investigate at the warehouse and even refusing to tell his new girlfriend Sara about Vincent. He also worries about him whenever he goes out to help Catherine solve cases. He begins to notice that Vincent has developed feelings for Catherine and instead of discouraging him, suggests he tell her how he feels. He spends much of his time spare time researching Vincent's mutations and finding ways to develop a cure for him.
J.T. most likely knew about Catherine before they ever met due to the fact that Vincent had a newpaper clipping of her from nine years ago. When she first discovers Vincent and becomes involved with him, J.T. is very distrusting of her and wants her to stay away from them, even calling himself "The President of the stay-away-from-Catherine club". His cold attitude towards her begins to thaw around Basic Instinct when they work together to find and stop Vincent from handing himself over to Muirfield. He realizes that Catherine is as devoted to protecting Vincent as he is. In Trapped, they work together again to try and stop Vincent's blackouts with Catherine managing to lure Evan away from his forensics lab so that J.T. could work in there undetected for two hours in order to formulate a serum to remedy the blackouts. He becomes aware of the fact that Vincent and Catherine have developed feelings for each other and appears to support the idea of them pursuing a relationship. When Alex Salter comes back into Vincent's life and he becomes torn between her and Catherine, J.T. supports Catherine and even feels sorry for her when she's forced to go to Alex's parent's cabin to save Vincent from Muirfield In Cold Turkey. He takes her side again In Trust No One when Vincent complains that she's shutting him out after his trip with Alex to the cabin.
Sarah Holland previously dated J.T, but she did not know the truth about J.T's life with Vincent.