Chained in Time - Rutter Books, #1

In 1888, Jack the Ripper, prowls London's East End, leaving bloody slaughter in his wake. A century later, History repeats itself. Marie Kelly is haunted by horrifying dreams in which she is pursued through the gloomy alleyways by a dark shadow that seeks to destroy her, as it once did her near-namesake, Mary Jane Kelly. Marie experiences Mary's terror and despair as her own. The two series of murders are linked fundamentally in a way that the police cannot prevent - even if they identify the modern killer, even if they kill him.
Marie and the Ripper are 'Chained in Time'. As Marie's personal crisis grows, a young Authorised Firearms Officer, W. D. C. Julie Rutter, is assigned as her bodyguard.