I've often had similar thoughts---that it's ghoulish and disrespectful to the victims to show interest in murder cases. I've even said that the media shouldn't talk about them, that they are nobody's business but the victim's family, the accused, and the family of the accused.
However, it is so common for people to have great interest in murder cases that I can't help but feel you're being a little hard on Paul here. I remember seeing an interview with Debra Tate, the sister of Sharon Tate, in which she said, "I can't stand the thought of people oogling over her death." I just had to laugh a little, not because I couldn't sympathize with the sentiment, but just because massive numbers of people had already been "oogling" over Sharon Tate's death for over thirty years by the time Debra made the comment. And also it seemed just so naive to think it could possibly be any different.
Authors have made livings by writing true crime books. They write them because they sell. We've all heard of Ted Bundy, haven't we? We've all heard about him because writers, both in the media and book authors, write about what people want to read. And the crime is always murder, they don't write books about insider trading. I think it's human nature. Yes, there's a lot of Schadenfreude in the interest, and Schadenfreude is not an attractive quality, but it's a very human quality.
I can understand you being turned off by true crime and hoping that no child of yours becomes an aficionado of it. My point is that I don't think Paul is that unusual or that much of a freak.