The Work of a Narrow Mind by Faith Martin
When ex-DI Hillary Greene, now working for the cold case squad, is handed the case of the murder of a harmless old woman, who'd been brutally battered to death in her own home, she is determined to track down the killer. But with her lover pressing her for an answer to his proposal of marriage, and a new boss to break in, it's not going to be easy, especially when one of the newer members of her team seems to have his own private agenda for being at Thames Valley. An agenda that is leading him inexorably into very big trouble indeed. It's a good job then that Hillary is a multi-tasker - nobody is going to get away with murder on her watch.