The Gatekeeper (2002)

Adam Fields is a rage-filled U.S. Border Patrol Agent who often crosses the line in his job. A member of a vigilante group, Fields decides to go undercover with a hidden camera and cross with a group of undocumented immigrants. His plan goes awry, however, when the group is forced to work for a drug ring. Suddenly, Fields realizes that he has more in common with the migrants and their search for home, family and freedom than he thought.