An appellate judge ordered the house arrest Friday of former Mexican President Luis Echeverria on suspicion of directing police and military snipers to open fire on student protesters in a 1968 massacre.
Echeverria, 84, has been an elusive target of government efforts to prosecute leaders of Mexico's former ruling party believed responsible for hundreds of killings during the so-called dirty war of the 1960s and '70s.
Twice in the last year, judges have rejected government indictments against Echeverria accusing him of a role in Mexico's deadly crackdown on dissidents.
But Judge Angel Mattar Olivar overturned a lower court Friday, saying there was sufficient evidence for Echeverria to stand trial on a charge of genocide in the killing of students during a demonstration in Tlatelolco Plaza on Oct. 2, 10 days before the 1968 Olympic Games opened here.
Investigators found that at least 360 snipers were involved that day, including some who fired from an apartment owned by Echeverria's sister-in-law, according to their review of government documents and witness accounts.
The official death toll is 38, but rights organizations say at least 300 died.
Defense attorney Juan Velazquez said Echeverria -- who was interior minister in 1968 -- is not guilty and will prove his innocence at trial. The lawyer criticized prosecutors for resorting to genocide charges because the statute of limitations on murder had passed.
"There was no genocide," he said. "The deaths came during a confrontation with snipers and authorities. There was no policy of exterminating a population. It's totally out of proportion."
The government's defense in dirty-war allegations has long been that rogue elements of the military carried out torture and killings in response to armed insurgents' attacks on soldiers.
President Vicente Fox, after his election in 2000, appointed a special prosecutor to investigate abuses against dissidents by the Institutional Revolutionary Party. That party ran Mexico for seven decades until the victory by Fox and the National Action Party six years ago.
In December, the office of the Special Prosecutor for Social and Political Movements of the Past submitted a draft report to Fox, summarizing its four-year investigation. It said the worst abuses took place during Echeverria's 1970-76 presidency.
The military, for example, created secret bases in the southern state of Guerrero where suspected insurgents were tortured, interrogated and killed, the draft report says. Military flights from Acapulco dropped victims into the Pacific. Soldiers surrounded villages to starve out suspected rebels or burn the buildings. Rape and torture were common, the report says.
Under Echeverria, it says, the government "implemented a genocide plan that was closely followed during his reign," and more than 500 people remain unaccounted for.
Genocide in Mexico carries a minimum prison sentence of 20 years. But until Friday, there was little sign that anyone would be brought to trial.
Special prosecutor Ignacio Carrillo Prieto has had mostly setbacks. His final report has never been released. And Fox administration officials in April talked of closing his office after several courtroom losses.
The Supreme Court has dismissed genocide charges against Echeverria for his alleged role in the 1971 killing of student marchers.
"If they don't finish this next step, then the whole thing will have been a farce," said Felix Hernandez Gamundi, a Mexico City engineer who was arrested at the 1968 Tlatelolco protest and jailed for three years.
Echeverria is eligible for house arrest instead of jail because he is older than 70. No trial date has been set.
Carlos Martinez and Cecilia Sanchez in The Times' Mexico City Bureau contributed to this report.