Be advised that this book is NOT designed to teach Spanish grammar to the complete newcomer. It does not even discuss grammar, so if you have never studied Spanish, you'll need to look elsewhere first to learn to conjugate verbs, etc. This book has many examples of useful phrases, but it also contains many long vocabulary lists which--for the beginner--offer little to no guidance on how to use them in a gramatically-correct sentence.
I found this book to be a bit too broad in it's approach to teaching Spanish for a specific field of interest ("law enforcement"). I would have preferred it if the author would have assumed that the reader already had a functional vocabulary and was just looking for the unique terms and expressions used in police work. As it is, you have to sift through a lot of general-purpose vocabulary and phrases to get to the meat--the unique terms and expressions you need as a cop but wouldn't have learned in Spanish 101, or even Spanish 301. If you're a beginning student of Spanish and already know the basics of grammar, you may appreciate the lists of basic words and phrases.
Where the book does cover a topic of importance to me, I found it did not go into enough detail. For example, there is a section on DUI's, but the phrases it offers are only of a very general nature and do not convey all of the instructions an officer would need to process a DUI. With all due respect to the author, it is apparent from what is missing from this book that he does not work in law enforcement and lacks an indepth understanding of the type of information that a police officer would want to convey and obtain. Phrases like, "You're in violation of a no-contact order," or, "If you don't go to court, the judge will issue a warrant for your arrest," should be included in a 410 page book for law enforcement but I can't find any indication here how to convey those ideas.
Much of my work with Spanish-speaking individuals involves gangs, but this book never directly addresses gangs and the associated terms that go with them ("brincar" means "to jump in," for example). Also, there is no mention of Spanish slang or swear words in this book. Slang is a subject in itself, but every Spanish book for law enforcement should contain at least a list of slang terms that relate to officer-safety ("cuete" means "gun," for example).
This book could also benefit from a good index since the table of contents is extremely basic. Finding info on a particular topic takes some searching.
In fairness to the author, I must address a previous reviewer's implication that the book uses nonstandard Spanish. On page 210 under "The Raid" it correctly lists "This is the police" as "Somos la policia," and on page 8 under "What's your name?" it says that the proper way to answer someone asking your name is to say, "Soy..." for "I'm..." However, the book's cover does indeed contain the error the reviewer mentioned.
Despite the above citicisms, this book is certainly not without its merits. Every single Spanish word has an accompanying phonetic spelling as a pronunciation guide, which beginners may find very helpful. And although the treatment of some subjects is more superficial than I would have liked, a broad range of subjects are discussed. If you knew everything in this book, you would at least be able to get by in most law-enforcement situations. But if you're looking for something with a more complete listing of advanced terms and phrases (more "meat"), a much better alternative is Living Language's Essential Spanish for Law Enforcement.