NEW YORK -Alleged drug cartel boss Rafael Caro Quintero, who spent decades in prison in Mexico for the murder of a U.S. drug enforcement agent, pleaded not guilty in a U.S. court on Friday to drug trafficking charges that could result in his execution.

Caro Quintero spent 28 years in prison in Mexico after being convicted of the 1985 murder of former DEA agent Enrique "Kiki" Camarena, one of the most notorious killings in Mexico's narco wars. He was expelled from Mexico on Thursday as part of the biggest handover of suspected cartel members in years.

The violent story of the capo and murdered DEA agent featured prominently in Netflix's 2018 "Narcos Mexico" series.

"We have waited 40 years for this day," Frank Tarantino, the special agent in charge of the DEA's New York division, told reporters outside the federal courthouse in Brooklyn. "If you come after us, if you hurt one of us, there is no obstacle we cannot overcome, there is no border we cannot cross."

Caro Quintero spent 28 years in prison in Mexico over Camarena's murder. He denies involvement and was released in 2013 on a technicality, but was recaptured by Mexican authorities in 2022. He was indicted in absentia in 2020 in Brooklyn on drug trafficking and weapons charges.

Caro Quintero, 72, landed at John F. Kennedy Airport in New York on Thursday night. On Friday, he appeared in a large ceremonial courtroom packed with more than 100 DEA agents and was led toward the defense table by U.S. marshals, his wrists shackled with the same handcuffs Camarena once carried.