Shooter (2007)

A marksman living in exile is coaxed back into action after learning of a plot to kill the President. After being double crossed for the attempt and on the run, he sets out for the real killer and the truth.
 
Director:   Antoine Fuqua
Writers:  Jonathan Lemkin (screenplay), Stephen Hunter (novel)
Stars:   Mark Wahlberg, Michael Peña, Rhona Mitra