MEXICO CITY, MEXICO -- The last time María Concepción Ávila González, 55, and her mother, Matilde González, saw their brother and son, Jesús Ávila González, was on April 5, 1974. He was 23 years old and was studying economics at Instituto Politécnico Nacional, a prominent public university in Mexico.

But he also was a social activist who belonged to the Partido de los Pobres, a guerrilla group, during Mexico’s “Guerra Sucia,” or Dirty War as it is now known. The Dirty War was an internal struggle from the 1960s to the 1980s between the government, led by the Partido Revolucionario Institucional political party, and left-wing student and guerilla groups.

“From the moment that he disappeared, we looked for him for three years,” says Ávila González, who was 26 at the time.

She says they were unable to get any information from the police.

“They simply ignored us,” she says. Through newspaper articles, she and her mother learned in 1977 about Rosario Ibarra de Piedra, the leader of Comité ¡Eureka!, a group of mothers looking for daughters and sons who had been arrested and disappeared because of their political ideas.

“When I met Doña Rosario Ibarra, she already had my brother on a list of missing persons,” Ávila González says. “Then, we didn’t know what a political prisoner was, nor the political struggle, nor parties nor anything. From that moment, we got involved in the political struggle. In every protest, in every banner, there was a hope for us.”.

Led by a group of mothers, relatives of the disappeared are still looking for hundreds of missing family members. They opened Casa de la Memoria Indómita last year to serve as a memorial museum and cultural center. Relatives say the initiative is keeping their fight alive by offering hope that they will one day reunite with their loved ones.

In 2001, the Mexican government, under the first president who was not from the Partido Revolucionario Institucional in 70 years, opened the first investigation into forced disappearances by the government during the Dirty War. It created the Fiscalía Especial para Movimientos Sociales y Políticos del Pasado, which registered 789 forced disappearance cases from 1968 to 1988.

In 2006 the Office of Special Prosecutor Ignacio Carillo Prieto, released a report that detailed the government’s violent repression of student groups during the Dirty War. The report accuses three past presidents of a sustaining an official practice of violence against guerrilla groups and student protesters. The report accuses former presidents between 1964 and 1988 of “massacres, forced disappearance, systematic torture, and genocide.”

Despite acknowledging the policy and registering the disappearances not one case has been solved.

Meanwhile, relatives of the disappeared continue to look for their missing family members. The group of mothers led by Ibarra de Piedra named their organization Comité ¡Eureka! After the exclamation used to express triumph on a discovery, says Celia Ibarra, one of its members. But they also are known as “doñas,” a respectful title for elderly women in Mexico. Since 1975, the