Mean Streets: Book 1
From the Infected Universe

With his friend lion shifter Roan McKichan no longer in the picture, former sex worker Holden Krause is now working as a detective investigating cases in Seattle. When he receives a request to investigate a rather unusual case for Big Mike, a local drug dealer, he ignores the potential hazards in working for such a client and takes it on.
But Holden hasn’t given up his vigilante ways, occasionally seeking violent retribution for those ignored by the justice system. There’s a man stalking the streets, assaulting anyone he perceives to be trans or gender nonconforming in any way. When the brutality escalates, the case becomes personal for Holden.
If he cannot juggle being both a detective and a vigilante, his taste for blood and danger might finally catch up with him.