After Mr. Sandoval moved to France in 1985, he taught at the Université of Marne-la-Vallée, outside of Paris, and at the New Sorbonne University. He obtained French citizenship in 1997, according to his lawyer.
At the New Sorbonne, he worked at the Institute of High Studies for Latin America, a highly regarded institution known for welcoming exiles who fled the dictatorships in Argentine, Brazil or Chile. Many of his colleagues felt Mr. Sandoval’s presence there had left a stain on the institute.
“It is pathetic that someone accused of crimes against humanity, a torturer, was allowed to train young people at university,” said Denis Merklen, a professor at the institute who, like Mr. Sandoval, holds French and Argentine citizenship.
Mr. Sandoval was hired as a lecturer at the institute in 1999, when France’s current education minister, Jean-Michel Blanquer, ran it. Through an aide, Mr. Blanquer denied knowing at the time Mr. Sandoval was hired, about the charges he is now facing.
For more than 20 years after the end of the dictatorship, two amnesty laws in Argentina protected officials involved in the regime’s crimes. The laws were overturned in 2005 — the same year Mr. Sandoval was dismissed from the New Sorbonne, although for reasons unrelated to the accusations he currently faces.
His name was connected to the crimes committed by the dictatorship in 2008, when the Argentine newspaper Página 12 published an investigation about him.
Olivier Compagnon, a professor of contemporary history who ran the institute from 2015 to 2019 and taught an introductory class on Venezuela with Mr. Sandoval in 2003, said students complained that Mr. Sandoval was obsessed with weapons and security issues. He also questioned how the institute could have recruited someone who had so few qualifications.
Mr. Sandoval’s resume from the late 1990s, which The New York Times saw, starts in 1985 and states that he taught at a dozen institutions, but didn’t specify which universities he had attended.
“It’s nonsensical,” Mr. Compagnon said. “Today we would never hire someone with such a vague profile and resume.”
Mr. Abriata’s relatives said they hoped justice could now be done.
“We expect a fair trial with all the legal guarantees so his constitutional rights are respected, which none of the 30,000 who were disappeared enjoyed,” Ms. Abriata, Hernán Abriata’s sister, said.
Elian Peltier reported from London, and Daniel Politi from Buenos Aires.