"All the Silent Bones" leans more towards a typical crime thriller than horror, but the (admittedly limited but crucial) touch of horror pervading the book is so well-done, I'd have no problem if the book were marketed as wholly horror. I enjoyed it from start to finish, despite the ending building on elements of the story very much in the background (and including an off-putting "villain monologue" at the end as well). It's also a slow burn, the most important part of the plot (driving the rest of the story forward) appearing midway through the book.
I would not consider any of this a flaw, however, since Funaro's writing shows incredible craftmanship, impressive attention to detail, and superb dialogue and characterization. It manages to tell an original story with the main characters being a group of male friends, portrayed both as kids and adults, without going the way of "IT" or "The Body" (as it usually happens), it captures the Rhode Island atmosphere perfectly, the themes of family issues and overall traumatic childhood are handled in an exemplary manner (with neither much fanfare nor turning everything into a crusade or a social message), and, finally, the darkness it deals with is displayed with uncanny precision and compelling realism.
My single complaint would be that the novel is so good, I really wanted more from it in relation to horror. It was disappointing that Bobby, the kid whose life derails when something bad happens to him as a teen, and who, as an adult, turned out to have so much potential for creepiness, all but remained untapped. I'm not saying that Funaro wasted a perfectly good character, who might have turned the story into a fascinating horror tale of possession and associated supernatural phenomena (the book does include these); I'm only noting that the author presses harder on the mystery thriller/police procedural aspects of the story, and, after some point, unnecessarily foregoes horror altogether.
In sum, this is a page-turner, and will easily satisfy lovers of horror, urban crime stories, detective tales, and psychological thrillers. Highly recommended!