Day 2: 6:00 A.M.-7:00 A.M. - S2-E23
Plot hole: When Kim is brought back to the police station for the last time, the officer explains to her that they now know it was Gary Matheson who killed his wife, and that they are still looking for him. Why then, would Kim and her police escort not even consider the possibility that he might be hiding at his home when they arrive to get Kim's belongings? Even if the police searched the house once before, you would have to be insane to allow a teenage girl to enter the home of a known murderer on the loose. Beyond that, Kim herself never seemed to consider the threat.
Answer: According to Jack in season 5, Nina was "deep cover" before the pair ever met, so it's safe to assume she was recruited before she joined CTU. As for what her primary mission was, who knows? Perhaps it was to gather sensitive intel and pass it on to her superiors. Given that she worked for an intelligence agency, it's not a stretch. Or perhaps we may find out in season seven.
Cubs Fan ★