Again, someone has to write those books. It may as well be you. It is legal, profitable, and downright intriguing. People want to know how things such as murder or kidnapping can happen. It can happen to any one of us.
Kids believe that strangers are ugly, like monsters.
If you are interested in writing about true crime, begin by searching local newspapers for stories. Anytime you see an article that looks interesting, clip it and put it in a true crime clippings file. If there are more articles about the same crime, then you know it is intriguing enough to warrant your attention. To discover the answer to that question will take research. These questions will help you decide if you have a story worth considering.