Mr. Abriata was one of about 5,000 people who disappeared at the Higher School of Mechanics of the Navy, or ESMA, which was converted into Argentina’s largest clandestine detention center.
The former detention center is now a human rights memorial.
Some of those suspected of these crimes, like Mr. Sandoval, moved abroad after the end of the dictatorship, delaying their prosecution and extending the wait of family members who sought justice for their missing relatives.
“This means the beginning of the end to his impunity, an impunity he enjoyed since the day he was in charge of a gang at the ESMA and kidnapped my brother,” said Laura Abriata, Mr. Abriata’s sister.
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.