I loved it. A really high quality twisty police story which makes one think about the trade-offs we have to make when applying the desire to be truthful and "do the right thing". It put me in mind of that scadi (?) series called "Rough Justice".
I intend to look up this author and read some of her other tales. She clearly knows what she is doing, and has a background in the police which makes it all the more credible. Some fine acting, too.
Unusually for me, I'm praising ITV instead of BBC this time
Arb.