Soul, by Tobsha Learner

In 1860, seventeen–year–old Lavinia Huntington is transported from her Irish village to start a new life in Mayfair, London, as the wife of a gentleman anthropologist, thirty years her senior. A year later she is standing trial for his murder.
In modern–day Los Angeles, forty–year–old Professor Julia Huntington, geneticist, returns from a field trip to Afghanistan. She has received a prestigious commission from the US Defence Department to research a genetic propensity to kill without remorse. At the same time, she discovers that her husband has betrayed her terribly.
This is a story that crosses generations, a story of two women and their struggle with obsessive love and revenge. Part murder mystery, part psychological thriller, part commentary on genetics and human behaviour, sexual jealousy and betrayal, Soul is both provocative and unputdownable.