I mostly enjoyed this show up until the final 10 minutes. The motives for the murders are poorly explained making the conclusion weaker than it should have been.
There's also parts of the story that don't bear any critical examination: the sudden release from prison with no lawyer involvement, Julian's conviction, his not suing for wrongful conviction even when the detective admits significant mistakes to his face, the double doping of Julian by Isabelle and Janet, parish's motives toward Olga, Sundays reunion. It feels like either the scriptwriters weren't quite up to the job or the editors left too much on the cutting room floor.
Then there's the casting, Bernthal is a decent enough choice, perhaps slightly too much of bruiser looking guy for the character. Mol gives a flat performance, as always. O'Donnell is a poor pick for a poor character, Rosie doesn't ever really act she adjusts the volume of her own personality, if her nip\tuck character was her turned to 11 here we see her at 3. Moreover the detective Sunday character is a walking cliche, badly written and actually almost entirely superfluous to the story. Brochere does what she can with another badly written character, complex motivations boiled away to cartoonish levels.
Perhaps 7 is generous but 6 would be low, it's inbetween. But don't be too put off, it's decent enough but not one that you'll be rewatching at any point.