True Crime
Among other things, I write about true crime cases (3 books published thus far) though these have all concerned crimes between 60-150 years ago. When I proposed a trilogy of cases to my publisher about a fairly recent case, I was referred to the legal department to go over just this concern. If the crime is solved, you don't have as many problems. If YOU propose to solve it, there are resounding liability issues. Maria Flook, in her book INVISIBLE EDEN, managed to write a book about an unsolved case without problems -- she used her own story/background as the framing device for the case. You might want to take a look at it. It's not my proverbial cup of tea, style-wise, but it's interesting.
In his book WRITING BESTSELLING TRUE CRIME AND SUSPENSE, Tom Byrnes has a chapter on this issue. A good resource.
Good luck!