Blood of the Prodigal, by P. L. Gaus

The book is about the mistrustful co-existence of Amish and English in small town Ohio.   The mystery involves a history professor, Mike Branden and his wife, Caroline, who are drawn into the search for a missing Amish boy through their friendship with a pastor.  Turns out the boy was taken by his father, who had been banned from his community ten years before. There are parts that make sense and others that don't.  I didn't realize that this was the first book in the Ohio Amish Mystery Series.  I felt like I was missing backstory that had been presented in a previous book. Readers say Gaus gets better.