Fiction by Harlan Coben.
This story begins with the main character, Will Klein, at his mother's deathbed. She tells him that she believes his brother, who had disappeared eleven years ago after being accused of a terrible murder, is still alive. He decides it must be wishful thinking on his mother's part, until he finds evidence that she might be right...
This was an exciting thriller with several great twists, including a shock (or two) at the end.
I also read recently by this author: Missing You