A special prosecutor appointed to investigate Mexico's most important human rights crimes said on Thursday he would bring charges against two dozen former military and civilian officials for the 1968 student massacre at Tlatelolco.
The prosecutor, Ignacio Carrillo, said that former President Luis Echeverria Alvarez could be among those named in the indictments to be filed in March.
If so, it would be the government's second attempt to win a genocide indictment against Echeverria, now 83, and considered the oldest survivor of the authoritarian government that used fraud and corruption to control the country for more than seven decades.
Last July, prosecutors charged Echeverria and several of his former aides with genocide in the killings of at least 25 student protesters who were attacked with clubs and chains by shock troops as they marched peacefully through Mexico City in 1971.
The indictment, the first against a former Mexican president, was considered a signal event.
But the next day, a Mexican judge dismissed the charges, saying that the 30-year-old statute of limitations had passed.
That decision is currently being reviewed by Mexico's Supreme Court.
In a telephone interview, Carrillo said he would not wait for the Supreme Court's decision in that case to file the indictments in the Tlatelolco massacre, in which a military unit opened fire on student protesters gathered in a downtown plaza shortly before the 1968 Olympics.
Hundreds were killed and wounded, and the Tlatelolco massacre was a turning point in Mexico's struggle for democracy and fueled an era of social unrest.
Over the next 15 years, the government began violent campaigns against its real and imagined enemies.
At least 275 people were kidnapped and killed in the so-called dirty war, and independent human rights activists say the real toll is twice as high.
Carrillo said he expected to file another 30 indictments in the dirty war killings before the end of the year.