Game of snipers
(Book)

When Bob Lee Swagger is approached by a woman who lost a son to war and has spent the years since risking all that she has to find the sniper who pulled the trigger, he knows right away he'll do everything in his power to help her. But what begins as a favor becomes an obsession, and soon Swagger is back in the action, teaming up with the Mossad, the FBI, and local American law enforcement, as he tracks a sniper who is his own equal...and attempts to decipher that assassin's ultimate target before it's too late.