Enrique Camarena

A Mexican drug lord convicted of kidnapping, torturing and murdering a DEA agent in 1985 has been released from jail, a move that has incensed U.S. law enforcement, Slate reports.

The U.S. expressed deep frustration with a three-judge court that decided to overturn Caro Quintero’s sentence on the argument that he should have been prosecuted in state not federal court.

Slate reported that the U.S. is working with Mexican authorities to nab others responsible for the murder of DEA agent Enrique “Kiki” Camarena.”

The Justice Department is among the U.S. agencies expressing concern with Mexico.

U.S. Rep. Michael McCaul, Texas-R, called the decision to overturn Quintero’s sentence “insulting” and warned of a “negative impact” between U.S. and Mexico relations.