The Ladykiller by Martina Cole

George Markham has a nasty little hobby, one that erupts into an orgy of vicious sexual depravity.
Patrick Kelly is a hard man. His one soft spot is his daughter, and when she falls victim to the Grantley Ripper, Kelly wants revenge.
The DI in charge of the case is Kate Burrows. She feels for Kelly but her growing involvement with a known villain is putting her career at risk . . . As the forces of law and order and London's underworld converge in a huge manhunt, Kate fears she'll lose everything she's ever cared about . . . to the ladykiller.