Real review to come when it's not 3:30am!
Later: This is a 5-star debut, easily.
I did guess the killer pretty early on, and the ending did seem to come on rather quickly and felt a tad rushed, but neither of these details outweigh the major plusses of this book.
So many first books are so rough - the writing isn't as good as it could be (or at all), the plot is predictable, the characters flat - all the usual first-time author issues. When I'm reading a debut, I keep that stuff in mind, because the first book is usually pretty rocky, but a good writer will get it worked out by the 2nd or 3rd installment and we're smooth sailing. Margaret Mizushima suffers from very little of those missteps. She's a pro right out of the gate. The writing is good (from a technical perspective), the dialogue believable, the story interesting, the mystery compelling, the characters are fully-realized beings acting in realistic accord with who they are.
The characters are just so well done - revealed in tantalizing bits and pieces. The dog stuff is fascinating, totally realistic, and factually correct. I love that the "sidekick" is a veterinarian, and a single dad at that! The main character is very likable and the author has done a fantastic job of showing the character's presentation to the world versus how she is inside herself, and how those two don't always match up, and the consternation that causes the character. That's some skillful characterize right there, folks.
In addition, right up front the author tells us what the main character (Mattie) wants more than anything, which is "to be found." By the end of the book you get the impression that Mattie wants more than merely "to be found," or perhaps that "being found" means different things in different circumstances. Again, skillful characterization.
I noticed only one boo-boo which should have been caught by editing: near the end, Robo's muzzle is removed twice within the same 30 seconds, and by two different people. That's the only thing I caught, though.
It was a highly enjoyable read and I cannot WAIT for more books in this series. I absolutely will read every one of them. Mattie and Robo make a terrific team, and the vet is a neat guy. The other cops, Brody and Johnson, and Sheriff McCoy all have room to grow and develop, and I'm so excited to see how they do.
I stayed up til 3:30 one night to finish the book, so I definitely recommend it.