GUATEMALA CITY (Reuters) - Former Guatemalan dictator Efrain Rios Montt was found guilty on Friday of genocide and crimes against humanity during the bloodiest phase of the country’s 36-year civil war and was sentenced to 80 years in prison.

Hundreds of people who were packed into the courtroom burst into applause, chanting, “Justice!” as Rios Montt received a 50-year term for the genocide charge and an additional 30 years for crimes against humanity.

It was the first time a former head of state had been found guilty of genocide in his or her own country.

Rios Montt, now 86, took power after a coup in 1982 and was accused of implementing a scorched-earth policy in which troops massacred thousands of indigenous villagers thought to be helping leftist rebels. He proclaimed his innocence in court.

“I feel happy. May no one else ever have to go through what I did. My community has been sad ever since this happened,” said Elena de Paz, an ethnic Maya Ixil who was two years old in 1983 when soldiers stormed her village, killed her parents and burned her home.

Prosecutors say Rios Montt turned a blind eye as soldiers used rape, torture and arson to try to rid Guatemala of leftist rebels during his 1982-1983 rule, the most violent period of a 1960-1996 civil war in which as many as 250,000 people died.

He was tried over the killings of at least 1,771 members of the Maya Ixil indigenous group, just a fraction of the number who died during his rule.

A throng outside the court chanted “Justice! Justice!” when the guilty verdicts were handed down on Friday.

“They convicted him, they convicted him. I can’t believe it,” said Marybel Bustamante, whose brother was ‘disappeared,’ a euphemism for kidnapped and murdered, the day that Rios Montt took power.

The human rights group Amnesty International hailed it as the trial of the decade.

‘FULL KNOWLEDGE’

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“He had full knowledge of everything that was happening and did not stop it,” Judge Yasmin Barrios, who presided over the trial, told a packed courtroom where Mayan women wearing colorful traditional clothes and head-dresses closely followed proceedings.

Nobel Peace Prize winner Rigoberta Menchu was among them.

“Today we are happy, because for many years it was said that genocide was a lie, but today the court said it was true,” she said.

Barrios called a hearing for Monday to discuss compensation for the victims of Rios Montt’s rule.

Rios Montt’s intelligence director, Jose Rodriguez Sanchez, also stood trial, but he was acquitted on both charges.

During the trial, which began on March 19, nearly 100 prosecution witnesses told of massacres, torture and rape by state forces. At one point, the trial hung in the balance when a dispute broke out between two judges over who should hear the case.

Rios Montt denied the charges in court on Thursday, saying he never ordered genocide and had no control over battlefield operations.

“I am innocent,” he told the courtroom, sporting thick glasses and a gray mustache. “I never had the intent to destroy any national ethnic group.

“I have never ordered genocide,” he added, saying he took over a “failing” Guatemala in 1982 that was completely bankrupt and full of “subversive guerrillas.”

Former U.S. President Ronald Reagan provided support for Rios Montt’s government and said in late 1982 that the dictator was getting a “bum rap” from rights groups for his military campaign against left-wing guerrillas during the Cold War.

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He also once called Rios Montt “a man of great personal integrity”.

Defense attorneys said earlier they would appeal if Rios Montt was convicted. They argued that prosecution witnesses had no credibility, that specific ethnic groups were not targeted under Rios Montt’s 17-month rule and that the war pitted belligerents of the same ethnic group against one another.

DIVISIVE CONFLICT

Rios Montt has been under house arrest for more than a year. The right-wing party that he founded changed its name this year to distance itself from its past.

Guatemala’s civil war ended with peace accords signed in 1996 but the Central American nation remains a deeply divided society with very poor indigenous areas.

President Otto Perez, a former army general during the civil war, says he was part of a group of captains that stood up to Rios Montt.

Declassified U.S. documents from the civil war years suggest Perez was one of the Guatemalan army’s most progressive officers and that he played a key role in an ensuing peace process.

But Perez was himself implicated in war crimes during the trial when one prosecution witness testified that soldiers under his command had burned down homes and executed civilians during Rios Montt’s rule.

Perez has argued that genocide did not take place during the war, underlining the divisions that persist in Guatemala over the conflict, which pitted leftist insurgents against a string of right-wing governments.

Perez, who took office in 2012, is the first military man to run the country since the war ended, and rights groups were concerned he could interfere with human rights trials.

Courts in Guatemala have only recently begun prosecutions for atrocities committed during the conflict.

Until August 2011, when four soldiers received 6,060-year prison sentences for mass killings in the northern village of Dos Erres in 1982, no convictions had been handed down for massacres carried out during the war.

A judge who initially presided over pre-trial hearings cast a new shadow of doubt over the Rios Montt case on Friday when she confirmed a decision she had announced on April 18 to wind back proceedings to November 2011, and void all developments since then.

Prosecutors insist that decision is illegal and are preparing legal challenges to the ruling, while defense attorneys have argued that the decision is binding and the trial should never have proceeded.