This is an excellent police drama. The first two seasons focus on one murder, and the many avenues taken to solve the crime. The last two seasons each deal with a single crime. This was very well cast and written. I honestly can not say enough good about this series, except for the fact that is is only four seasons long. I had extremely high hopes that it would keep going once Netflix picked it up. Unfortunately, as is the case with many very good dramas, it ended before its time. Give this show a watch, you will not regret it.