U.S. authorities have dropped as many as a dozen murder charges against reputed Mexican drug lord Joaquin "El Chapo" Guzman.

Without announcement, federal prosecutors in New York are reported to have removed the brutal acts from a list of formal charges filed against the notorious Sinaloa drug cartel leader.

Plans now call for Guzman to be extradited to the U.S. on a slew of drug trafficking charges, which some legal experts predict could be easier to convict him in connection with.

Guzman Being Held in Maximum Security, Mexican Prison

Guzman is currently being held in a Mexican prison following his recapture four months ago after a second prison escape. The government there recently announced plans to extradite him to the U.S., where he faces numerous drugs charges in cities across the country impacted by his multibillion-dollar operations.

Attorneys for Guzman have indicated they plan to fight his extradition on several legal fronts. Federal prosecutors from New York's eastern district are reported to have won the right to prosecute him first after competing with rival cases including Chicago, San Diego, and El Paso for the justice department's approval.

"It is a calculus that involves a lot of different issues, but what it boils down to at the end of day is: who's got the best charges and who's got the best evidence," said Theresa Van Vliet, a former chief of narcotics at the justice department. "It's as simple as that."

Brooklyn Charges Once Centered on a Dozen Murders

Filed in Brooklyn in September of 2014 when U.S. attorney general Loretta Lynch was still the district's top federal prosecutor, a grand jury indictment previously charged Guzman and an associate with 12 murders that were carried out in Mexico over an eight-year span beginning in 2000, along with two attempted murders and multiple murder conspiracies against rival cartels.

Among the murders was that of Roberto Velasco Bravo, Mexico's director of investigation for organized crime, who was assassinated in Mexico City in early 2008.