It should be interesting ... probably won't be solved without extra content... but I can tell you now: Mrs. Thornton loves Captain Lee but is maybe just a little scared of him... when she was working for Commissioner Thomas, the commissioner crossed that fraternization line and accidentally revealed the depth of the corruption in that office. Mrs. Thornton is the only survivor of that office. Two deputy commissioners ended up in jail. Commissioner Thomas and his two remaining deputies who became acting commissioners died -- one resisting arrest, two just scared to death. Guess who took out ALL FIVE?
That said, go back and read the story again. Someone is already planning to leave the force, thereby potentially solving the fraternization problem...