Kent Drake is Dr. Maura Isles's assistant. He worked as an army doctor in Afganistan before coming back to Boston.
In the episode, "Sister Sister " Kent kisses Maura and Maura is concerned that Kent may like her (policy is that you cannot date your subordinates in the Medical Examiner's Office). Turns out, he kissed Maura to distract her from the fact that, due to his time in Afghanistan, he is traumatized at the prospect of notifying patients' families with Cause of Death. At the end of the show (spoiler), it is revealed that Kent may actually be interested in Jane Rizzoli .
In There Be Ghosts, we learn that he is a fan of the sport of shinny, that his hobbies include taxidermy (he does mice and then dresses them in seasonal outfits), and that he his a fan of a certain American rock band. He learned to love ramen when he was in the army (For Richer or Poorer). In "Ocean Frank", Kent is set to oversee the Commonwealth of Massachusetts' Medical Examiner's Office during Maura's sabbatical.