Carrillo Leyva -- who is the son of famed drug lord Amado Carrillo Fuentes and whose uncle, Vicente Carrillo Fuentes, alias "Viceroy," now runs the criminal syndicate -- was arrested in April 2009 and charged with being a member of an organized crime group, carrying an illegal weapon, homicide, electoral fraud and falsifying documents, El Excelsior newspaper says.
Judge Fermin Rivera Quintana dismissed charges that connected Carrillo Leyva to organized crime. Two other charges were dismissed because of lack of evidence. Carrillo Leyva was expected to post bail so he could be released, while he awaits trial on the remaining charges.
The judge's ruling is a blow to the Mexican government's efforts to fight large criminal organizations.
The Juarez Cartel has been battling with the Sinaloa Cartel for control of the country's main drug corridor along the U.S. border.