The Burning, by Jane Casey
I read Jane Casey's first novel, The Missing, and was not as nearly taken with it as her second, The Burning, which felt similar to BBC's "Prime Suspect" (with Helen Mirren), but with a young Irish detective named Maeve.
One reason why I didn't like her first novel was that I didn't find her main character, Sarah Finch, to be very likable. She ended up being a teacher after she hated school, and she didn't seem to get any enjoyment out of her job. I cannot relate to this, but my husband tells me that he thinks it sounds British...he thinks that more people in the UK go into teaching without really being called to do so. That might be true.
At any rate, I prefer Maeve. She has to put up with her English colleagues' misogyny and crap about her Irish ancestry, but she is a strong and complex character. She's working on a case to catch a London serial killer who likes to beat his female victims to a pulp and then set their bodies ablaze. It's more of a police procedural (hence the Prime Suspect comparison) than a mystery book, but I liked it.
The other thing I appreciated about this book was the publisher didn't dumb it down for Americans...as in, they didn't change the British terms and language (like they did in Harry Potter, for example). Most Americans will not know what a bacon buttie is...but that's okay! They can look it up if they want to know.
I will keep reading Casey's books (she has three more Maeve Kerrigan books published with another one on the way), and I'm so glad she redeemed herself after the first one.