NPR has some interesting details on the nuclear physicist and his wife who were arrested and charged with trying to sell nuclear information to Venezuela: Pair Accused Of Trying To Help Venezuela Get Nukes.

CARRIE JOHNSON: Well, the key figure in this case is Pedro Mascheroni. He was born in Argentina, but he became a U.S. citizen in 1972. He worked as a nuclear physicist in a secret unit called the X Division at the Los Alamos Lab for about 10 years. And he’s described as a brilliant scientist, and he had access to highly secret information about the design of nuclear weapons through his job.

But things seemed to go south for him. He got into a big fight with the Department of Energy after speaking out over its failure to fund a project that he highly supported. The government wound up investigating him and yanked his security clearance in 1987. He ultimately left and filed a lawsuit. And sources tell me he kept on being disgruntled all these years.

His wife, Marjorie, also worked at Los Alamos, but she was a technical writer and editor, not a scientist. Prosecutors say she went along with her husband’s plan and accompanied him to drop off some documents and even edited some of his materials.

BLOCK: But, Carrie, this is a guy whose security clearance was yanked more than 20 years ago. What would he have had that would have been of value?

JOHNSON: Sources are telling me everything he needed to know he kept in his head. This is a very smart scientist who had Q-level security clearance - one of the highest in the government. And he was able to reconstruct most of what he wanted to know and tell the Venezuelan government, allegedly, by just thinking back to his experience in the business.