This is another category that is “new,” but not really so. As I have mentioned in Old School Roots, mysteries have been around a long time and in both Western and non-Western countries. But this category only started appearing in bookstores in the 90’s.
There are two major types within this category: 1. Mysteries that take place in countries or settings other than typical Western ones, such as novels set in Japan or 2. Novels featuring protagonists within Western countries (especially the US) who are members of a racial or cultural minority.
But the latter type has blurred into the mainstream, as what is “mainstream” has diversified to include minorities, sometimes as part of an ensemble (especially in Police Proceedurals, which are usually teams of detectives.