Las poquianchis (De los pormenores y otros sucedidos del dominio público que acontecieron a las hermanas de triste memoria a quienes la maledicencia así las bautizó) (1976)

In the mid-1970s in the Mexican state of Guanajuato, authorities discover a clandestine burial ground full of the corpses of murdered prostitutes. The suspects are three sisters known as "Las Poquianchis" They were very religious, but they owned brothels and recruited poor girls with false promises of jobs, then forced them into prostitution, and killed many of then,