Special prosecutors in Mexico have filed genocide and kidnapping charges against a former Mexican president.
Luis Echeverria has never admitted any personal responsibility
Luis Echeverria, now 83, is accused of ordering a massacre of student protesters in 1968, days before the Olympic Games opened in Mexico City.
As many as 300 people may have died when government agents hidden among regular soldiers opened fire on students, prosecutors allege.
A Mexico City judge must now rule on whether the case should go to trial.
Mr Echeverria is the first former Mexican president to face the possibility of charges for human rights abuses allegedly committed during his time in office.
He was serving as interior minister and head of national security at the time of the massacre.
Special prosecutor Ignacio Carrillo filed the charges after a judge ruled in July that Mr Echeverria could not be charged over separate killings in 1971.
Mr Carrillo said his investigations had exonerated the Mexican army of responsibility for the massacre, and said he hoped to end 37 years of "impunity and injustice".
Luis Echeverria's lawyer Juan Velasquez said he believed the new charges would be rejected much like Mr Carrillo's last accusations.
"It is exactly the same thing: the deaths of that day in 1968 were the result of a confrontation, not a state policy," Mr Velasquez said.
Mexican students still mark the 1968 Tlatelolco massacre
Mr Echeverria has acknowledged that some died in Tlatelolco Square in 1968.
He denies prosecution allegations that he posted snipers on scores of buildings to fire into the crowd and gave orders to fire.
He faces a kidnapping charge over the 1969 disappearance of activist Hector Jaramillo.
Several others are named in the case accused of involvement in the Mexico City massacre.
Mexico's current President, Vicente Fox, has vowed to punish public figures found to be responsible for killings and oppression in the past.
Hundreds died or disappeared during Mexico's "Dirty War" on leftists under Mr Echeverria's leadership between 1970 and 1976.