Helen Mack Chang (born 19 January 1952) is a Guatemalan businesswoman and human rights activist. She became an outspoken advocate for human rights after her sister, anthropologist Myrna Mack Chang, was assassinated by the Guatemalan military on September 11, 1990. She pursued prosecution of her sister's assailants, including ground-breaking cases in the Inter-American Court of Human Rights, achieving convictions of one assailant and a high-ranking colonel. The Guatemalan government acknowledged responsibility in 2004 and has paid compensation to Mack and her family. In 1992 Mack received the Right Livelihood Award in Sweden, and has received other awards for her human rights work. In 1993 she established the Myrna Mack Foundation, to support the prosecution of her sister's murder and do other work for human rights, establishing programs and support for victims. In 2010, she was appointed by Guatemala President Álvaro Colom to lead investigations into continuing police corruption and recommend changes. Early life and education Helen Mack Chang was born in Barrio San Nicolás, Retalhuleu, Guatemala. Her mother was Chinese and her father was Mayan. She had an older sister, Myrna, who became an anthropologist. Human rights activist During the Guatemalan civil war, Mack's sister Myrna worked with indigenous Mayan rural peoples. She documented their displacement by fighting and the scale of the government's attacks on them. Myrna was stabbed to death in 1990 near her office in Guatemala City by unknown assailants, believed to be ordered by a government that wanted to silence her public criticism. Beginning in 1991, Mack pursued the prosecution in Guatemala of those suspected of the crime, which included several men trained at the US Army School of the Americas (later renamed the Western Hemisphere Institute for Security Cooperation). After more than a decade of seeking justice in Guatemala, Mack took the case to the Inter-American Commission on Human Rights in Washington, DC, and later to the Inter-American Court in Costa Rica. Two years later, one of Myrna’s killers, former Army Sergeant Noel de Jesús Beteta, was convicted in a groundbreaking decision. The court sentenced him to 25 years in prison. The prosecution of the case resulted in the trial of two colonels and a general "as the intellectual authors of the murder; the highest-ranking officials in Guatemala ever to be tried for human rights violations." In 2002, Colonel Juan Valencia Osorio was convicted in absentia for his role in ordering her murder, and sentenced