The summons - Peter Lovesey

Summoned at night, Peter Diamond is collected from his West London flat by two policemen who drive him to bath, where once he headed the murder squad. Out of touch in his retirement, he knows nothing of an audacious escape from Albany Prison.
Four years before, he investigated the bizarre murder of a Swedish woman journalist. Now the convicted murderer is at large. Worse, he has already kidnapped the Assistant Chief Constable's daughter. His demand? That the case be re-examined. He will deal only with Diamond. In reopening this matter, Diamond faces a challenge that makes huge demands on his patience, to work with the senior policemen he scorns, and courage, to deal with the violent man he sent down.