Although the result of a side-plot is devastating (if you are invested in the main character) the story keeps you engaged. The resolution -- while not 100% satisfactory -- is realistic in terms of the legal system. 

I highly recommend Val McDermid's various series. She is a master of pacing, her characters are dynamic and real, and her plot lines are always interesting and often informative.

Even when I figured out whodunit, I didn't know the WHY until near the end, which is a great sign of McDermid's skill as a mystery writer. That said, I wish some of the dialogue was less expository, and I wish she didn't have such internalized fatphobia. Still, I am enjoying the Karen Pirie series.