Detective Rutledge makes a compelling protagonist--with the voice of a dead man criticizing his every step, he's completely aware that he's inches from failure, disgrace, and most likely suicide. It's a pity that his mystery, while it ties up very neatly, relies too heavily on coincidence.
This is a very well constructed small town mystery, in which no one has an obvious motive and everyone has a hidden one. The characters are vivid, sympathetic in their own ways, and baffling. Rutledge himself is under pressure for political reasons both inside and outside of Scotland Yard, and it keeps the tension going nicely. The plot unfolds, with plenty of well constructed red herrings. The author has enough insight into human nature to show people's frailties without demonizing them, and to construct reasons why "good" people would do awful things and "bad" people generous ones. The ending is unexpected, but in retrospect, all the clues were there.
So why only a three? Rutledge suffers from post traumatic stress syndrome of a particularly picturesque manifestation. From what I understand of how this works, well, it doesn't work that way. For all that it's popular in fiction, people who hear voices don't generally hear the voice of a specific, real life person, who merely sits in the back of their heads making snarky commentary. And schizophrenia isn't typically triggered by PTSD--they're two seperate illnesses. But I'm willing to grant artistic license. Maybe for this one guy, that's how it works. But the plot ends up hinging on not one, not two, but four different characters each suffering from PTSD, each with entirely unrelated, unrealistic, but completely plot-driving symptoms. And it's too much. I'm willing to accept one sensationalistic fictional mental disorder. Not four. (I was actually willing to accept up through the first three. It's the climactic one that finally broke my suspension of disbelief.)
Also slightly annoying is the fact that this is so obviously pitched as the beginning of a series. The overall plot is very carefully constructed to have multiple parallels to Rutledge's own situation, so that his personal damage makes the case that much harder. I would have liked to see him work through some of that damage as a result. Not a cure, of course, but it would have been nice to see him recover a little confidence, come to a working relationship with the voice in his head, something. Despite the personal nature of the case, though, Rutledge has no discernable character arc. He's the same as when he started. As is his unexplainedly malevolent boss, who's still stroking his moustache and thinking "I'll get you, Gadget, next time, next time..." including ending the book on a literal set of periods of ellipsis.
So basically, I loved this book until the last twenty pages. The writing is beautiful. The characters are fantastic. The solution to the mystery does, in fact, explain everything. But the flaws are quite irritating. There's enough potential here, though, that I'd be willing to give the series one more try to see if the author works out some of the kinks as he gets more experienced.