Crime of Passion by A.M. Halford

Dragos, a half-dragon, is not happy about this latest case. Supernatural murders of humans weren’t exactly anything new to him, it was actually his job, but these were just gruesome. His partner, Rozalia, and he were only called in after the fourth body was found. Meaning they were now playing catch up. The addition of a third party wasn’t making his mood any brighter.
Neculai, a half-demon, can tell that Dragos is less than thrilled to have him on this case. After all, what can human science tell them about supernatural deaths? Fortunately for Neculai he’s very good at what he does, and he doesn’t use human science but instead a form of alchemy created especially for the HBIA (half-blood investigative agency).
As they work together Dragos and Neculai quickly come to notice the attraction between each other, though when they act on it something unimaginable happens. These two must not only learn to work together to catch a serial killer, they also must come to terms with the newest turns in their own lives.