Here are the reasons the first court gave for reversing his conviction (you can use Google translator for this one.) In essence, the court granted his writ of Amparo finding Mexico's federal courts did not have jurisdiction to try him (as opposed to a Mexican state court) and that Camarena was not a diplomatic official. After the U.S. and DEA made a stink, the decision was reviewed and reversed by the Mexican Supreme Court.
Caro-Quintero, in his letter to Mexican President Enrique Pena Nieto and other officials, says the DEA has made his family's life a nightmare and he's been punished enough. He urges the President to reject the U.S. bid for his extradition and asks that Mexico put justice over revenge.
In his letter, Caro Quintero alleged that U.S. agents are carrying out “an absurd persecution” of him and his extended family, and that Mexicans should stand up for him on patriotic grounds against a nation that “always feels superior.”
...“If I still had any debt to the state and to society, I have already paid it,” Caro Quintero said in the letter, which was dated Nov. 11.
...“This infernal nightmare against my loved ones and against me does not arise from legal verdicts or from matters of law but rather . . . from resentment and a desire for vengeance of those who from outside our borders insist on accusing me of crimes I did not commit,” Caro Quintero wrote.
Mexico's Attorney General, Jesus Murillo Karam, has confirmed the letter reached President Pena.
I've uploaded a copy of the actual letter in Spanish here.
Caro-Quintero was tried and convicted in Mexico for (among other things) the murder of Camarena. He served 28 years of a 40 year sentence as a result. Mexican law does not allow extradition for crimes tried in Mexico.
To further complicate matters, last month two ex-DEA agents came forward and said the CIA was in cahoots with Caro-Quintero in his marijuana operations and Cuban CIA operatives were involved in Camarena's torture and murder. A former CIA contract pilot backs them up. A third ex-DEA agent, Celestino Castillo III, author of "Powderburns: Cocaine, Contras and the Drug War," said the two ex-agents and pilot "are right on the money." More here.
