This novel is a stand-alone novel by C.J. Box. It's from 2008 and now out in paperback.
A 34 year old couple, Jack and Melissa McGuane are childless, and Jack notes he's 'shooting blanks'. So they adopt a beautiful daughter and have her for 9 months when they receive notice that the teen aged dirtbag father, the son of a powerful and very influential federal judge, and his father want to take custody as the father never relinquished his parental rights. Well, this isn't to occur without resistance and the book goes from there.
The son is in with a Mexican gang and the father has his own issues.
It's not a particularly pleasant book to read for a parent, but it is a book that draws you in quickly and it's one that really made me want to find the conclusion, which is not what I expected.
And I'd recommend it as the characters are good to read about. The uncle who has been known to do unusual things. The friend who is a detective. The gay friend who is very connected in town and pays for it. The 'pure' judge, who isn't. And so on.
It's good to have friends.