Kim is a good, confident police officer. She was partnered with Kevin Atwater on Patrol under Trudy Platt. She started seeing Adam Ruzek during this time, who broke off his engagement to be with her. Atwater was then promoted to Intelligence. Kim was told by Voight that she wasn't chosen because he didn't tolerate in-house romance.
Kim was then paired with Sean Roman. She was shot during a call and given the chance to join Intelligence by Voight but refused because she wanted to help Roman through his depression and guilt of her getting shot. However, Roman then left after an injury left him unable to remain active.
Tay then joined Kim as her partner but was also very soon transferred out. Kim felt she'd done her job on Patrol and asked Voight if she could still join. He let her back.
Kim was engaged to Adam as his third fiancee. However, they broke it off because Kim felt he wasn't committed, but they got back together soon after.
Kim has a sister, Nicole, who was seen first in Little Bit of Light when she came to visit. They are very close and after Nicole was assaulted on her first night out in Chicago, Kim took leave from her job to help her sister through it, in Last Minute Resistance
Nicole's daughter, Zoe, is also very close to Kim. She was first seen in 8:30 PM after a hospital explosion left Zoe in critical condition under Kim's care while Nicole and her now ex-husband, Jordan, were away. Kim stayed with Zoe, very upset and worried about her until she was saved.
Kim was working with Kevin Atwater as a Patrol officer.
Kim and Ruzek began preparing for their wedding, but Roman told her to give Ruzek the 'push test'. If Kim told him to push the wedding date and he agreed, he didn't want to get married in the first place. She asks him and he agrees and she's left upset but she doesn't think more of it then just a test.
In Looking Out for Stateville, the two families had planned a dinner so that they could both meet each other. However, Adam tells Kim that his dad had a 'work thing' come up so he won't come, then tells Kim to say sorry to his parents on his behalf. She's left deeply upset, because Adam cancelled on her for no reason too. Adam doesn't see this and then tells Kim to come over with him to Molly's. She's angered and tells him that the reason he cancelled was because he knew that meeting her parents would mean he'd have to get real, which he can't because he didn't ever plan on marrying her. He tries to explain but she tells him she's letting him "off the hook", giving back the engagement ring and breaking up with him.
In Hit Me, Kim tells Trudy that she was giving in her transfer papers. Trudy pulled her aside and figured out it was because of Ruzek. She told him to reconsider her choice because it could affect her life. Kim doesn't want to hear it and says she's sure. Trudy then asks Erin to talk to her. Erin tells Kim that she'll regret her decision. Kim is sure but then Erin says that this will follow her around for the rest of her career, because everyone will know she moved out because of her ex, and it wouldn't make it easy considering she's a woman and that's already hard enough. She tells her that she needs to ask herself if Ruzek is more important than the career she has so carefully built up. Kim decides to stay.
- Marina went on maternity leave after Last Minute Resistance, with the in-show explanation being that she needed to help her sister, Nicole, who had been attacked.