The Hidden Man - David Ellis

A finalist for the LA Times Book Prize
A little girl, snatched from her bed in the dead of night...
They knew who killed her. They couldn't prove it. 26 years later, her brother Sammy doesn't care about proof. He only cares about justice. Now, only his childhood best friend, attorney Jason Kolarich, can save Sammy from a life sentence for killing a killer.
To defend Sammy, Jason must do what authorities could not, decades ago—prove the guilt of the pedophile who killed Sammy's sister. But a mysterious benefactor, "Mr. Smith," suddenly appears, offering money, resources, even alibis for Sammy's defense. And he will stop at nothing—threatening the lives of Jason and his family—to control the outcome of the case. As the trial draws near, Jason races against time to save his family from Mr. Smith's team and his friend Sammy from life in prison, while two crimes, decades apart, converge in a stunning verdict.