Desert Saints is a 2002 crime thriller film starring Kiefer Sutherland as a hitman named Arthur Banks, alongside Melora Walters as Agent Bennie Harper.
Arthur Banks (Kiefer Sutherland) is an Ivy League-educated hitman for Latin American drug cartels who picks up solitary women, uses them as cover for a hit, then kills them.
Over the years, he has become wary of the FBI's attempts to catch him, including by use of satellite and security cameras, which leads him to mostly stay in rural desert areas when not working.
On the road, Banks confides to Harper that he hates his job but hasn't had a chance to get out of it for years until now.
She tells Banks that she expects the FBI will be so happy to catch and question him that she'll depart with the payoff without much problem, which is why she leaves him alive.