Federal authorities in Texas arrested a man believed to be a top operative for the Gulf Cartel this week. During a raid in Brownsville, other men and women potentially tied to the criminal operation were also apprehended.

Federal authorities arrested Carlos Fabian “El Cuate” Martinez and several others in South Texas. Martinez is the son-in-law of Osiel Cardenas Guillen, the supreme leader of the Gulf Cartel who is currently serving a 25-year-prison sentence for drug trafficking conspiracy.

Since the initial arrest this week, the individuals have gone before U.S. Magistrate Judge Ronald Morgan for an initial hearing and learned their cases would be moved to Houston and be held without bond.

The indictment has not been released or unsealed. Breitbart Texas sorted through court records and was able to learn that at least 12 individuals will face charges, however.

The arrested individuals include Marco Antonio Medina, Pedro Calvillo Hernandez, Sandra Guerra Medina, Mireya Miranda, and Jose de Jesus Tapia Fernandez.

El Cuate is married to the daughter of Osiel Cardenas, the Gulf Cartel boss credited with establishing Los Zetas as his personal security detail at the time. He is described as a local businessman in the Brownsville/Matamoros area, however, he is alleged to be operating within the criminal organization in a kingpin-like capacity. A criminal history search in Mexico and in the U.S. does not show any prior arrests.

Martinez’s brother-in-law, Osiel Cardenas Jr., is also in federal custody awaiting trial on arms smuggling charges, plus a state assault charge in connection with a stabbing at a Brownsville bar.

Ildefonso Ortiz is an award-winning journalist with Breitbart Texas. He co-founded Breitbart Texas’ Cartel Chronicles project with Brandon Darby and senior Breitbart management. You can follow him on Twitter and on Facebook. He can be contacted at Iortiz@breitbart.com