Devices and Desires by P.D. James

When Commander Adam Dalgliesh visits Larksoken, a remote headland community on the Norfolk coast in the shadow of a nuclear power station, he expects to be engaged only in the sad business of tying up his aunt's estate. But the peace of Larksoken is illusory. A serial killer known as the Whistler is terrorising the neighbourhood and Dalgliesh is drawn into the lives of the headlanders when it quickly becomes apparent that the Whistler isn't the only murderer at work under the sinister shadow of the power station.