Chosen prey - John Sandford

In the mist and rain of a Minnesota spring, a shallow grave is found. It contains the body of a young woman, apparently strangled. When the murder is connected with a brilliantly-executed erotic drawing, where the victim's face has been grafted onto a pornographic internet image, Lucas Davenport becomes involved. More of the drawings come to light and Davenport, with the help of a local sheriff's deputy, makes a grisly discovery. The drawings may represent more murder victims, strangled with a starter rope from an antique outboard motor.
As Lucas investigates further, he uncovers a web of deceit, related to a series of young women involved in the arts. All of them had some connection to the local university, and all of them had a new boyfriend who remained unseen by their friends. There the trail seems to end until further investigation of the grave site results in an horrific discovery.
On the misty, oak-covered hillside south of Minneapolis, the case begins to come together in Lucas' mind, but the mixture of ferocious intelligence and madness which he faces means that the deaths must continue, that the chosen prey must be stalked...