Arthur W. Upfield 
The Bone is Pointed [EPUB ebook] 

Jeffrey Anderson was a big man with a foul temper — a sadist and an ugly drunk. When his horse The Black Emperor, an animal as mean as its owner, came home riderless, no one cared. And no one cared when no trace of the man could be found. But five months later, Detective-Inspector Bonaparte is called in — and he is determined to solve the mystery. With his usual tenacity he takes up the cold trail. What happened to Anderson, to his hat, to his stockwhip, to his horse’s neck-rope? Bony must rely on his eyes and his wits to help him find the answers, for the local inhabitants, both black and white, are keeping their own secrets.
Bony — a unique figure among top-flight detectives — BBC