I agree with USAF1969. The book is ok and holds the reader's interest, but the main character is neither likeable nor admirable to this reader.
Texas Rangers are among the elite of law enforcement officers. Skilled, determined, and very professional. Yates, on the other hand, is a wild card, repeatedly defying both local police and his own supervisor, butting into the investigation, compromising evidence, harassing an individual he doesn't like because he wants this man to be the killer, not because there is hard evidence against him. He is indeed terribly immature and the real Texas Rangers wouldn't allow him to be a one man vigilante force.
Plus, speaking as a female, Yates is awfully full of himself and his attraction for the local women, who, with the exception of his ex-wife are all pining away for him while he dithers among them at first, but then immediately forgets about them when he sees the girl singer from the country band playing at his favorite roadhouse.
Sorry, Mr. Patterson, but this is one series I will not be following.