Broken Prey — John Sandford

The first body is of a young woman, found on a Minneapolis riverbank, her throat cut, her body scourged and put on display. Whoever did this, Lucas Davenport knows, is pushed by brain chemistry. There is something wrong with him. This isn't a bad love affair.

The second body is found three weeks later, in a farmhouse six miles south. Same condition, same display--except this time it is a man. Nothing to link the two victims, nothing to indicate that the killings end here.