A federal judge declined to throw out narcotics-trafficking charges against a man who alleges he was tortured by Mexican authorities while American agents looked on.In a written opinion this week, Chief U.S. District Judge Ruben Castillo concluded he was blocked by legal precedent from dismissing the indictment against Jesus Raul Beltran Leon on the basis of outrageous government conduct.Beltran purportedly served as a bodyguard for a son of drug kingpin Joaquin “El Chapo” Guzman.Following his arrest in …