Kickass Bookstore Owner Heroine

I've read lots of cozy mysteries where the female owner of a bookstore is the amateur sleuth heroine. I enjoyed those books, so I was eager to read this thriller where the female owner of a bookstore is a tough, kickass private eye. It sounded like it would be an interesting new twist on a type of book that I enjoy. Perhaps because of the bookstore element, I think I was expecting a private eye along the lines of Kinsey Milhone or Sharon McCone. Nikki Griffin is much more violent and not as smart as I expected. I think perhaps the fact that the author used initials instead of a first name and there was no author photo on the book set up some false expectations. If I had known the author was male before I began the book I would have expected something very different.