I really wish I could give half stars. This is a 2.5 star review for me.
The story itself was gripping . . . when it finally got to the climax, and that didn't happen until the last third of the book. However, when a book is as riddled with grammatical errors as this one is, it's hard for me to take it very seriously. Little things like using apostrophes when they weren't necessary because a word was being pluralized instead of showing possession (this was particularly evident when pluralizing a family's name), using "that" instead of "who" when talking about people, and one glaring continuity error (referenced under the spoiler tag) made enjoying this book very difficult. I felt like for the first 2/3 of the book, there were a lot of needless details. I get why the author explained all the things Carmine and Haven did, and why she explained Vincent doing what he did to Haven on the anniversary of his wife's death. And it was nice to see Haven's first chance to celebrate holidays like Halloween and Christmas. The interactions with several minor characters didn't seem as essential as they were in the fanfiction, though.
The continuity error focused on the date of Maura's death. When Vincent goes to the cemetery to visit his wife's grave, it gives a date of death of 1996. From there on out, her murder is described as happening in 1997. In the long run, it was a minor detail, but it kept throwing me off.
I should note that I read this story to a certain point when it was available for free. The book version differs a lot from the fanfiction, and I have to give Ms. Darhower kudos for doing that. Sempre managed to keep my attention the way the fanfic could not. I enjoyed the book a lot more than the fanfiction. Again though, the grammatical errors really threw me off the entire time. Maybe mine is a technical brain, but I found myself annoyed at having to correct things in my head.
I give it 2.5 stars, because the story kept me reading when the fanfiction could not.