There is more information about Julio Porras (the main ICE informant in the Daily Beast piece) in this 2012 article from Reporte Indigo. Apparently Julio Porras is also Ramiro Chavez and he worked as an informant for the PGR during the same time he was providing information on Juarez Cartel activities to ICE.
http://www.reporteindigo.com/reporte/mexico/otro-gobernador-en-la-mira?page=1 (Reporte Indigo)
http://www.thedailybeast.com/articles/2014/07/01/u-s-visas-helped-fuel-the-juarez-drug-wars.html (Daily Beast)