Sworn to Silence follows Chief Kate Burkholder as she investigates a string of murders in Amish country. As a murder mystery, the book has excellent suspense, keeping the reader guessing at the identity of the murderer until the very end.

The pull of her Amish childhood against the realities of her grownup "English" lifestyle creates a realistic, like-able character in Chief Burkholder. Her struggles resonate with the reader. The book earns its "thriller" namesake through Castillo's detailed descriptions of gory victims of murder, exciting chases, and flagrantly depicted sexual perversion and assault.

Overall, though the plot, setting, and characterization are superb, Sworn to Silence does not stand out against the wide tapestry of murder mysteries. However, time will tell if Castillo can bring Kate Burkholder to new depths of authenticity and exclusivity.