Bad Men by John Connolly
Three hundred years ago, the settlers on the small Maine island of Sanctuary were betrayed by one of their own, and slaughtered. Now a band of killers has returned to Sanctuary to seek revenge on a young woman and her son, and the only people who stand in their way are a young rookie officer and the island's resident policeman, the troubled giant known as Melancholy Joe Dupree. But Joe Dupree is no ordinary policeman. He is the guardian of the island's secrets, the repository of its memories. He knows that Sanctuary has been steeped in violence, and that its ghosts will tolerate the shedding of innocent blood no longer. On Sanctuary, the hunters are about to become the hunted.