She has been instrumental in forcing the revelation of the complicity of the United States CIA in human rights abuses, particularly in Guatemala and other countries of Central America during the 1980s and 1990s.
Initially, she was trying to discover the fate of her husband Efraín Bámaca Velásquez [es], a Mayan guerrilla leader who was "disappeared" in March 1992 by the Guatemalan military.
Declassified US files revealed that he was tortured and killed by high level intelligence officials in the Guatemalan army, who were also working as paid informants of the CIA.
Among her clients in the early 1980s were Guatemalan Mayans who emigrated to Texas to escape from the death squads that were committing genocide against them during the civil war in their home country.
Specifically, Col. Julio Roberto Alpirez, a Guatemalan colonel who studied at the School of the Americas and was a paid informant or "asset" of the CIA, had ordered the murder.
[9] Moreover, the intelligence agency had a close working relationship with the Central American military death squads who "disappeared" Bámaca and had been funneling money to them despite a Congressional prohibition since 1990.
During April 1996, the American nun Dianna Ortiz was fasting across from the White House, seeking the release of CIA papers related to her case of abduction and torture in Guatemala in 1989.
As a result, President Bill Clinton ordered declassification of United States secret archives on the Velásquez murder and other human rights crimes committed by the Guatemalan military.