Desert Saints.

Banks is a hit man, the best, usually working for Latin American drug cartels. He picks up solitary women, uses them briefly for a job, then kills them. He's in the Southwest, headed toward Mexico, when he picks up Bennie, a woman leaving an abusive marriage, going to Paradise, Arizona. The film follows three tracks: Banks's slow recruitment of Bennie, the set-up for the hit at a swank resort in Mexico, and the FBI's close pursuit of Banks, whom they want alive in hopes he'll rat out his bosses. Bennie may not be who she seems, and there may be a chink in Banks's tough-guy armor. Guns, money, and a chance at Paradise.