The move by Mexico to allow the transfer of Rafael Caro Quintero to the United States signaled a potentially new era of cooperation in the drug war.

NEW YORK — Cartel leaders Rafael Caro Quintero and Vicente Carrillo Fuentes are set to be arraigned in a U.S. federal court in New York City on Friday, following their surprise transfer from Mexico. The pair were among 29 Mexican prisoners sent Thursday to eight cities across the U.S.

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.