NEW YORK – 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.

Zambada’s lawyer, Frank Perez, said only that the government’s decision “marks an important step toward achieving a fair and just resolution.” Prosecutors said last winter that they were having plea discussions with Zambada’s lawyer.

Prosecutors wouldn’t comment further Tuesday after unveiling their death-penalty decision in brief letters to judges. A request for comment was sent to Caro Quintero’s lawyer.

The cases are unfolding in the same Brooklyn federal courthouse where infamous Sinaloa cartel co-founder Joaquín “El Chapo” Guzmán was tried and convicted.

The Sinaloa cartel is Mexico’s oldest criminal group, with various incarnations dating to the 1970s. It is a drug trafficking power player: A former Mexican cabinet member was convicted of taking bribes to help the cartel.

Guzmán and Zambada built it from a regional group into a huge manufacturer and smuggler of cocaine, heroin and other illicit drugs to U.S., authorities say.

While Zambada was seen as the cartel’s strategist and dealmaker, prosecutors have said he also was enmeshed in its violence, at one point ordering the murder of his own nephew.

Zambada avoided capture for years, until he was arrested in Texas last year, after what he has described as a kidnapping in Mexico. One of Guzmán’s sons, Joaquin Guzmán Lopez, was arrested with Zambada and has pleaded not guilty in a Chicago federal court.

Caro Quintero headed the Guadalajara cartel, parts of which later merged into the Sinaloa organization. The White House has called him “one of the most evil cartel bosses in the world.”

Prosecutors say he is responsible for sending tons of heroin, methamphetamine, marijuana and cocaine into the U.S. and had DEA agent Enrique “Kiki” Camarena abducted, tortured and killed as revenge for a marijuana plantation raid. The killing was dramatized in the Netflix series “Narcos: Mexico.”