After finishing the book and comparing it to the synopsis I have to say I wasn't expecting the story to go the way it did. I didn't think the victim would be that character, I assumed maybe the husband or mother. Even afterwards I suspected everyone but the actual killer. Everyone else had a motive except the killer. Unless they had one that we never discover?
I think the only reason I didn't give it 5 stars was because of the reveal. I feel it was for shock value more than anything else and it definitely was a shock. Also the last page set a few months later left me with more questions I don't think I'll ever get answered.
The writing itself had me hooked from the beginning. I usually don't like to read thrillers too late but with this I had to know what happened. I suspected too many characters to have to wait. For a book around 400 pages I devoured it within a few hours.

Edit: After thinking about it for a few days I decided to give it 5 stars. The book stayed with me more than others have.