New Delhi, Aug. 6 -- U.S. prosecutors said Tuesday they won't seek the death penalty in their cases against Mexican cartel kingpin Ismael "El Mayo" Zambada and Rafael Caro Quintero, the drug lord charged with orchestrating the 1985 killing of a U.S. Drug Enforcement Administration agent.

Caro Quintero, 72, and Zambada, 75, have pleaded not guilty to an array of drug trafficking charges. The prosecutions are separate, but they similarly target two of Mexico's most notorious narcos.

It is unclear whether taking the death penalty off the table signals any possibility of a plea deal with either or both men. Their lawyers welcomed the decision but were circumspect about what happens next.

Caro Quintero's attorney, Elizabeth Macedonio, said ...