Castellanos had already granted several visas to people of Jewish origin who were persecuted by the Nazis. However, now it was part of a larger project: the handing over of false documents of Salvadoran nationality to people of Jewish origin. Castellanos then consulted Dr. Guerrero, who immediately agreed to that plan that saved the lives of thousands of Jews. According to the investigations, Dr. Guerrero would have contributed to writing the text of the document that was then given to them to save their lives.
