Raven Black by Ann Cleeves

When teenager Catherine Ross is found strangled to death suspicion falls on Magnus Tait, a loner who was investigated in the disappearance of a young girl eight years ago. Shetland Islands police detective Jimmy Perez, despite no evidence to the contrary, believes that Tait is innocent. With help from the mainland police, Perez delves into Catherine's life. Raven Black contains lots of details about the isolation and traditions of the Shetland Islands. The mystery is similar to other british police procedurals, but is not as complex as P.D. James, Deborah Crombie, or Ruth Rendell.