I gave up on John Grisham a long time ago for being too predictably formulaic, but I was caught in a weak moment at the bestseller rack, in the mood for nothing heavy, and lured by the idea that his newest book was non-fiction.
It's fiction. The Author's Note at the end of the book is a dead giveaway, thanking his heroes for all of their input, and conveniently neglecting to gather any input from his villains.

For a little perspective:
Link: The Truth Behind "The Innocent Man" & Ada, Oklahoma