She knew too much — far too much — and she had to die before she talked
From the back:
I stared down at the body of my wife. There was a lot of time and a lot of booze between Carla and me. I didn’t love her any more and I understood now that she was just a tramp. But even she hadn’t deserved to die like this, beaten and battered so that she was a mockery of what she had been alive. My name’s Jake Barrow and I’m a pretty good private eye. A pretty good man on the scent. I’ll find Carla’s nameless and faceless killers and before I get through with them, they’ll beg to die…