Murphy's Law by Rhys Bowen

Murphy's Law is the first mystery novel I have read by Rhys Bowen, but will not be the last. I enjoyed the story and her style of writing, but what a difficult life it was for those arriving in New York from other countries (mostly Ireland). The novel is the first in the Molly Murphy series.

From the cover:
Under drastic circumstances, Molly Murphy is forced to strike out into a new world. With the police right behind her, Molly concludes that her only chance at escape is a false identity and a steamship that will take her far away to America . . . Before she able to leave Ellis Island a man is brutally murdered, and coincidence and fate make her a suspect in a crime she didn't commit.