King first applied her genetics skills to human rights work in 1984, when she and her lab began working with Abuelas de Plaza de Mayo (Grandmothers of Plaza de Mayo) in Argentina. She used dental genetics to identify missing persons, ultimately identifying 59 children and helping return them to their biological families. Most had been born to women in prison who had been persecuted as political dissidents and were later "disappeared" by the Argentine military dictatorship during the eight-year "Dirty War" from 1976-1983. These children were often illegally "adopted" by military families without their mother's or other family consent.