Border Incident (1949)

To penetrate a gang exploiting illegal Mexican farmworkers smuggled into California (and leaving no live witnesses), Mexican federal agent Pablo Rodriguez poses as an ignorant bracero, while his American counterpart Jack Bearnes works from outside. Soon, both are in deadly danger from the ringleader, sinister rancher Owen Parkson, and find night on the farm to be full of shadowy film-noir menace...—Rod Crawford