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Press Release

Former Workers at Los Alamos Charged with Transmitting Classified Nuclear Weapons Data to Injure the United States

For Immediate Release
Office of Public Affairs

WASHINGTON – The Justice Department today announced that a scientist and his wife, who both previously worked as contractors at the Los Alamos National Laboratory (LANL) in New Mexico, have been indicted on charges of communicating classified nuclear weapons data to a person they believed to be a Venezuelan government official and conspiring to participate in the development of an atomic weapon for Venezuela, among other violations.


The 22-count indictment, which was returned yesterday by a federal grand jury in the District of New Mexico, was announced by David Kris, Assistant Attorney General for National Security; Kenneth J. Gonzales, U.S. Attorney for the District of New Mexico and Carol K.O. Lee, Special Agent in Charge of the FBI’s Albuquerque Division.

The defendants are Pedro Leonardo Mascheroni (Mascheroni), 75, a naturalized U.S. citizen from Argentina, and Marjorie Roxby Mascheroni (Roxby Mascheroni), 67, a U.S. citizen. Both were arrested by FBI agents this morning and made their initial appearance in federal court in Albuquerque today. If convicted of all the charges in the indictment, the defendants face a potential sentence of life in prison.


The indictment does not allege that the government of Venezuela or anyone acting on its behalf sought or was passed any classified information, nor does it charge any Venezuelan government officials or anyone acting on their behalf with wrongdoing. Further, the indictment does not charge any individuals currently working at LANL with wrongdoing.

Mascheroni, a Ph.D. physicist, worked as a scientist at LANL from 1979 to 1988 and held a security clearance that allowed him access to certain classified information, including “Restricted Data.” His wife worked at LANL between 1981 and 2010, where her duties included technical writing and editing. She also held a security clearance at LANL that allowed her access to certain classified information, including “Restricted Data.” As defined under the Atomic Energy Act, “Restricted Data” is classified information concerning the design, manufacture or use of atomic weapons; the production of special nuclear material; or the use of special nuclear material in the production of energy.


The indictment charges the defendants with conspiring to communicate and communicating “Restricted Data” to an individual with the intent to injure the United States and secure an advantage to a foreign nation. They are also charged with conspiring to and attempting to participate in the development of an atomic weapon, as well as conspiring to convey and conveying classified “Restricted Data.” The indictment further charges Mascheroni with concealing and retaining U.S. records with the intent to convert them to his own use and gain, as well as six counts of making false statements. Roxby Mascheroni is also charged with seven counts of making false statements.


“The conduct alleged in this indictment is serious and should serve as a warning to anyone who would consider compromising our nation’s nuclear secrets for profit,” said Assistant Attorney General Kris. “I applaud the many agents, analysts and prosecutors who worked tirelessly to bring about this prosecution.”


U.S. Attorney Gonzales said, “Our laws are designed to prevent ‘Restricted Data’ from falling into the wrong hands because of the potential harm to our national security.  Employees at the Los Alamos National Laboratory who have access to ‘Restricted Data’ are charged with safeguarding that sensitive information, even after they leave the lab.  This is absolutely necessary for our national security, and it is what the public expects.  Consistent with its responsibility to protect our national interests, LANL has cooperated fully in the investigation leading to the indictment of Dr. Mascheroni and Marjorie Roxby Mascheroni.”


“As is often the case with these types of investigations, this has been a long, painstaking, and methodical process.  I am exceedingly proud of the work done by our Special Agents and their close colleagues at the New Mexico U.S. Attorney’s Office.  I am also grateful for the assistance of and close collaboration with officials at the Department of Energy and Los Alamos National Laboratory,” said FBI Special Agent in Charge Lee.


According to the indictment, Mascheroni had a series of conversations in March 2008 with an undercover FBI agent posing as a Venezuelan government official. During these conversations, Mascheroni discussed his program for developing nuclear weapons for Venezuela. Among other things, Mascheroni allegedly said he could help Venezuela develop a nuclear bomb within 10 years and that, under his program, Venezuela would use a secret, underground nuclear reactor to produce and enrich plutonium, and an open, above-ground reactor to produce nuclear energy.


During these talks, Mascheroni allegedly asked about obtaining Venezuelan citizenship and described how he expected to be paid for his classified nuclear work for Venezuela. He also told the undercover agent he should be addressed as “Luke,” and that he would set up an email account solely to communicate with the undercover agent. Mascheroni later used this account to communicate with the agent and to arrange for deliveries of materials at a “dead drop” location, which was a post office box.


In July 2008, the undercover agent provided Mascheroni with a list of 12 questions purportedly from Venezuelan military and scientific personnel. In response, Mascheroni delivered to the dead drop location in November 2008 a disk with a coded 132-page document on it that allegedly contained “Restricted Data” related to nuclear weapons. Written by Mascheroni and edited by his wife, the document was entitled “A Deterrence Program for Venezuela” and laid out Mascheroni’s nuclear weapons development program for Venezuela. Mascheroni stated that the information he was providing was worth millions of dollars, and his fee for producing the document was $793,000, the indictment alleges.


In June 2009, Mascheroni received from the dead drop location another list of questions, purportedly from Venezuelan officials, and $20,000 in cash from the undercover agent as a first payment. On his way to pick up these materials, he allegedly told his wife he was doing this work for the money and was not an American anymore.


In July 2009, Mascheroni delivered to the dead drop location a disk that contained a 39-page document with answers to the questions. According to the indictment, the document was written by Mascheroni, edited by his wife, and contained “Restricted Data” related to nuclear weapons. In the document, Mascheroni allegedly reiterated that the information he had provided was classified and was based on his knowledge of U.S. nuclear tests that he had learned while working at LANL, but that he would state the document was based on open information found on the Internet if “our relationship/alliance does not work…”


In August 2009, the indictment alleges, Mascheroni and his wife met with the undercover agent at a hotel, where Mascheroni further discussed his nuclear weapons development program for Venezuela. Several months later, FBI agents questioned Mascheroni and his wife about the classified information Mascheroni had provided to the undercover agent, among other things. Both made a series of false statements in response, the indictment alleges.

This investigation was conducted by the FBI’s Albuquerque Division with assistance from the Department of Energy and LANL.


The prosecution is being handled by Assistant U.S. Attorneys Fred Federici and Dean Tuckman of the U.S. Attorney’s Office for the District of New Mexico, and Trial Attorneys Kathleen Kedian and David Recker of the Counterespionage Section of the Justice Department’s National Security Division.


The public is reminded that an indictment contains allegations only and that every defendant is presumed innocent unless and until proven guilty.


Updated June 9, 2023

Press Release Number: 10-1044