Q: In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.
Passage: American Paul Banner used to be a reporter working in London. Recently leaving his paper, he has gone freelance, so that he can focus more on chasing down facts and selling his stories once he gets them. He has no regrets in leaving his job as there will be no more deadlines or misguided editors to divert his attention. He starts up a news agency, Banners Agency, whose motto is "ferret out the facts and sell them to the highest bidder."
When showgirl Nina Duke is murdered, the press are all harrying the police for statements and facts but Banner hangs back and does a little work of his own to uncover the story. Nina, it transpires, was previously in jail for blackmail, so it is possible that this was why she was killed. Banner initially falls for the affections of rival reporter Pam Barnes, but his true affections lie with his secretary, Maxine (Hazel Court. 
A race to find the killer has Banner trying to get the story that the police cannot.
A:
What crime did the showgirl once commit?