I did some more digging, and I found this article in Spanish.
Mario Villanueva recibe 36 años de condena
It says that he was convicted of drug trafficking by a Mexican court and his original sentence of 6 years was increased to 36 years.
I'm all confused now. At the time, I thought he had been released from Mexican prison but then brought back in to await the U.S. extradition charges. The extradition charges were approved, but maybe he never made it to the U.S. and so now, he's serving time in Mexican prison again? But I don't understand where the original 6 years that the article mentions comes in. Regardless, it seems that he's been convicted of drug trafficking and may be in prison somewhere.
