The Calling of the Grave - Simon Beckett

When DI Terry Connor turns up on David Hunter's doorstep, it's an unwelcome reminder of the past in more ways than one. The two used to be friends before Connor's behaviour caused a bitter rift. And the news the policeman brings is even less welcome: the psychotic rapist and murderer Jerome Monk has escaped from high security prison.
Monk's is a name all too familiar to Hunter. Eight years before he'd part of an ill-fated Body Recovery team assembled to try and find the graves of Monk's teenage victims on the bleak expanse of Dartmoor. Only one of the missing girls' bodies was ever found, and Monk's own controversial involvement in the search led to more failure and a violent denouement. And now Monk is on the loose - and seems to be targeting anyone involved with the original search.
Then Hunter receives a mysterious appeal for help from Sophie Keller, a young woman who also worked on the operation, he suddenly finds that the past is far from dead and buried. Neither the events unfolding now, nor those from all those years ago, are quite as they seem. And as the maniac's bloody trail edges ever closer, Hunter is forced to question who he can really trust. Especially when his own life depends on it...