Dec. 3 (UPI) -- The Trump administration has sanctioned Mexican national Lucio Rodriguez Serrano as it attempts to close in on Rafael Caro Quintero, who authorities accuse of being a major drug trafficker and responsible for the nearly four-decade-old killing of a Drug Enforcement Administration agent.
Rodriguez Serrano was sanctioned Wednesday by the Treasury's Office of Foreign Assets Control as a Specially Designated Narcotics Trafficker under the Foreign Narcotics Kingpin Designation Act for working on Caro Quintero's behalf.
"Caro Quintero and Rodriguez Serrano, both natives of Badiraguato, Sinaloa, Mexico, have been lifelong friends," the Treasury said in a release. "In recent years, Rodriguez Serrano has helped Caro Quintero evade capture. Additionally, Rodriguez Serrano has engaged in real estate transactions at the direction and for the benefit of Caro Quintero."
The DEA has offered a $20 million reward for information concerning Caro Quintero, who tops its Most Wanted Fugitives list for being the alleged mastermind behind the kidnapping, torture and killing of DEA Special Agent Enrique "Kiki" Camarena in 1985.
Prosecutors have charged Caro Quintero with operating "a vast narcotics transportation network responsible for the manufacture and importation from Mexico into the United States of multi-ton quantities of heroine, methamphetamine and marijuana."
Caro Quintero has also been charged with conspiring to murder those who pose a threat to that narcotics enterprise, including Camarena.
The notorious drug trafficker had been serving a 40-year prison sentence in Mexico for Camarena's death but was released by a Mexican court in August of 2013.
The Treasury said Caro Quintero is a top priority for the DEA and that U.S. authorities "will not rest until he is apprehended."
"Targeting his associates and support structure is crucial to choking off his criminal enterprise once and for all," DEA Acting Administrator Timothy J. Shea said in a statement. "Today's action by Treasury is an important step in our joint mission to disrupt, dismantle and destroy violent drug trafficking organizations and in bringing Caro Quintero to justice."
The Justice Department has previously targeted others close to Caro Quintero, including charging his stepson Bryant Espinoza Aguilar in July and seeking the forfeiture of Mexican real estate in 2019 that he was accused of buying with drug proceeds.
The sanctions freeze all of Rodriguez Serrano's assets, property and interests in property in the United States while barring Americans from doing business with him.
The designation came a day after the Trump administration sanctioned a network of Colombian nationals and businesses for aiding the drug trafficking activities of the Clan del Golfo cartel.
The State Department said Wednesday in a statement that more than 2,200 individuals have been designated under the Kingpin Act.
"Rafael Caro Quintero and his years of drug trafficking have endangered and cost American lives," said Treasury Secretary Steven Mnuchin. "Treasury, in coordination with the DEA and other agencies, is committed to targeting Caro Quintero until he is brought to justice."