Typical British drama... OVERRATED SPOILERS BELOW!
People often like exploring different time periods, cultures or countries in their entertainment. An English/British accent however does not give lazy writing and inconsistent characterizations a pass. Subtlety is rarely a strength in overrated British dramas and they often cut corners unnecessarily, robbing an otherwise decent show of its integrity. I'll say that there are a few good and intriguing moments in this series once you see what the writers are up to and get used to it (late S1 thru late S2). But for the most part I found myself annoyed by characters that didn't make sense and the haughty self-absorbed attitude of the main character, a worn-out cliche of a detective.
Regarding some of these poor characterizations...
Ellie's teen son Tom (having disavowed his own mother when his father is arrested for the murder of his best friend) flips from unlikable and suspicious, to son-of-the-year! He's suddenly holding hands with mumsy, helping her and the rest of the town to run his acquitted father out of town on a rail. This supposedly is inspired after one lame rant from Ellie. The inexplicable character shift is all done after using him for the better part of 2 whole seasons as a weak plot device to make him look guilty of something.
Then there's Mark... Imagine your only son is murdered by a family friend. While this man is on trial you decide to potentially risk his conviction by secretly hanging out with his son in some weird woman's trailer, all while constantly being MIA and lying to your pregnant and still grieving wife. This is yet another weak and contrived plot device to create suspicion. But then suddenly Mark goes from lying, philandering moron to loving supportive husband and father in the blink of an eye to button up the season 2. By the end, they've spend so much time trying to create weak diversions you're not ever completely sure Joe (another inconsistent character) is actually guilty in whole or in part.
Season 3 is so depressing and sensationalist I actually stopped watching a couple of eps in. A friend I'd been watching with convinced me to finish what I'd started. It gets worse. The writing takes liberty by making the leads even more sanctimonious, arrogant and insufferable, while trying to make them also seem sympathetic and nauseatingly progressive. Arguably the most laughable moment in the series was watching Alec and Ellie take turns excessively berating a young detective that came forward late to tell them one of the suspects was her estranged father. Considering the fact that these two knuckleheads are the main reason Joe got to walk free from his murder charge in the first place, made this an even bigger joke. If this was such an issue in this little community why was Ellie (Joe's wife!!) even allowed to continue as a detective in Danny's murder case when Joe was brought in for questioning, let alone be given access to kick the crap out of him while in custody, ultimately ruining his prosecution.
Ed's arrest?? Not one single piece of physical or compelling evidence for it... all circumstantial and no connection to prior victims. There were other more compelling suspects with actual physical evidence against them. It made me wonder why the writers even contrived to include Ed and his daughter in the story other than to heap abuse on them.
Unless you're just so charmed by British accents that you'll watch anything... this is NOT recommended.