Episode 048: Todd Hulsey – Nuclear Weapons, Mascheroni Spy Case (Part 1)

Retired agent Todd Hulsey served with the FBI for 15 and a half years. However, he has, in total, 21 years of federal law enforcement service. Prior to obtaining his law degree and joining the Bureau, Hulsey worked for five years as a special agent with the United States Customs Service, now known as Immigration and Customs Enforcement (ICE). In this episode of FBI Retired Case File Review, Hulsey is interviewed regarding a nuclear weapons espionage case involving Pedro Leonardo Mascheroni and his wife Marjorie Mascheroni.  “Leo” Mascheroni was a theoretical physicist formerly employed at the Los Alamos National Laboratory in New Mexico. The FBI discovered that he had made contact with a foreign country and had offered to sell his expertise and assistance to build a nuclear weapons program for that nation. Hulsey supervised the Albuquerque Division case and the agents, analysts and surveillance group members who gathered the evidence needed to prosecute the Mascheronis for espionage. They both agreed to plead guilty to illegally passing  nuclear weapons program documents which contained information derived from classified and restricted data. He was sentenced to five years and she to one year in prison. Post Bureau retirement, Todd Hulsey runs his own law practice and operates  X Fed Productions, an entertainment consulting firm providing technical advice in the areas of national intelligence, law enforcement, and military operations to authors, screenwriters, video game developers, producers, and directors.

Special Agent (Retired)

Todd Hulsey

8/30/1998 – 3/31/2014









Nuclear Weapons Espionage

The following FBI overview, press release and newspaper articles provide additional background material on the Pedro & Marjorie Mascheroni nuclear weapons espionage case:

Former Los Alamos Lab Workers Sentenced – Nuclear Scientist and Wife Passed Classified Documents (FBI Video)

Former Los Alamos National Laboratory Scientist Sentenced to Prison for Atomic Energy Act Violations (Press Release)

New York Times – Couple Accused of Passing Nuclear Arms Secrets

New York Times – Zeal for Dream Drove Scientist in Secrets Case

“Leo” Mascheroni was a theoretical physicist formerly employed at the Los Alamos National Laboratory in New Mexico.









Jerri Williams

View posts by Jerri Williams
Jerri Williams, a retired FBI agent, author and podcaster, jokes that she writes about the FBI to relive her glory days. After 26 years with the Bureau specializing in major economic fraud and corruption investigations, she calls on her professional encounters with scams and schemers to write police procedurals inspired by true crime FBI cases in her Philadelphia FBI Corruption Squad crime fiction series featuring flawed female FBI agent Kari Wheeler. Jerri’s FBI for Armchair Detectives nonfiction series enables readers to discover who the FBI is and what the FBI does by debunking misconceptions about the FBI in books, TV, and movies. Her books are available as ebooks, paperbacks, and audiobooks wherever books are sold. She’s also the host of FBI Retired Case File Review, a true crime podcast with more than 300 episodes available on all popular podcast apps and YouTube.


  1. William IezziJanuary 4, 2017

    Fascinating case. I doubt that many people knew about this.

    1. Jerri WilliamsJanuary 4, 2017

      I have to admit that I don’t remember hearing about it. The story gets even better in Part 2.


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