Former dictator Jorge Videla was sentenced to life in prison Wednesday for the torture and murder of 31 prisoners, most of whom who were "shot while trying to escape" in the months after his military coup.

The conviction was Videla's first in 25 years for crimes against humanity, thrilling relatives who packed the courtroom, holding up grainy black-and-white pictures of the victims and shouting "murderers" at the defendants. Most of the two-dozen former military and police officials who were tried with Videla also received life sentences.

Videla, who led the military coup that installed Argentina's 1976-1983 dictatorship, is considered the architect of a dirty war that eliminated thousands of people in a crackdown on armed leftist guerrillas and their supporters.

The judges found Videla "criminally responsible" for the deaths of the prisoners, who were transferred from civilian jail cells to a clandestine prison where they were repeatedly tortured under interrogation before being killed.

Videla told the court that Argentine society demanded the crackdown to prevent a Marxist revolution and complained that "terrorists" now run the country.

Videla must serve his sentence in a civilian prison, the judges decided, ruling out the privileges he enjoyed after he was first convicted of crimes against humanity in 1985, as Argentina was struggling to return to democracy. Videla served just five years of a life sentence in a military prison before former President Carlos Menem granted him and other junta leaders amnesty.

After a concerted campaign to reform a judicial system packed with dictatorship-era judges, the Supreme Court overturned those amnesties in 2007, and current President Cristina Fernandez has encouraged a wave of new trials of former military and police figures involved in the clandestine torture centers where thousands of the regime's opponents disappeared.

This was the first of dozens of trials coming up for Videla, now 85.

Some of his co-defendants received lesser terms, and seven minor defendants whose cases were joined to Videla's were found not guilty.

It was the fifth life sentence for former Gen. Luciano Benjamin Menendez, who directed the early war against leftist subversives across much of northern Argentina.

The 31 victims in this case — many of them university students with links to armed leftist revolutionary movements — were taken to a clandestine center in Cordoba and tortured with methods including electric shock, rape, simulated asphyxiation with water and nylon bags and mock executions. They were left naked in cold wet cells through the winter, and were told their families would be killed if they didn't confess, survivors said.

Menendez told the court that it is historically revisionist to present armed leftist groups as passive victims with no responsibility for criminal acts. The Montoneros and the People's Revolutionary Army were already committing violent acts before the coup, he reminded the judges.

"They were combatants who took on certain risks," Menendez said. "It's not a crime against humanity to fight an armed combatant."

Videla and Menendez accepted responsibility for the crackdown but claimed they had to act as they did to prevent what they considered would be a greater tragedy — the transformation of Argentina from a conservative Christian society to a Marxist state.

Ricardo Alfonsin — son of the late President Raul Alfonsin, who helped put Videla and other junta leaders on trial 25 years ago and created the "Never Again" commission that documented thousands of crimes against humanity — said such arguments are meaningless coming from men who lack all moral authority.

Videla "represents the most absolute evil," Alfonsin told Radio Continental on Wednesday. It was Videla, he said, who "ordered them to torture, who ordered them to rape, who ordered them to kill or who tolerated them doing all of these aberrant things."

About 13,000 people were killed or disappeared during the dirty war, according to a government count. Human rights group estimate the figure is actually 30,000.

Seeking justice "is the only thing we have left in life. Our children haven't appeared — we don't know anything about them," said Nair Amuedo of the Mothers of the Plaza de Mayo human rights group. "At least these murderers were condemned for who they are."

(This version CORRECTS that Ricardo Alfonsin's father created "Never Again," which documented crimes against humanity.)