The Cater Street Hangman  by Anne Perry is the first in the Charlotte Ellison and Thomas Pitt series. The setting is the late 1800's just outside of London. A murderer is attacking young women in the street strangling them and tearing off their clothes. Charlotte's family is part of the rich upper class and the women she is allowed to associate with do not discuss such topics as murder, war or sex. the consensus is that the murdered women somehow did something to deserve being killed. However, when a maid of the Ellison household is murdered, suspicion falls upon the butler involving the household in the investigation. As they work together hunting the serial killer stalking the young women Thomas comes to admire Charlotte and she is interested in him but their social standing is far apart and romance seems impossible.