After President Otto Perez's resignation Sept. 3, Guatemalans head to the polls to elect a new leader. Perez has been jailed facing corruption charges. (Reuters)

— Just a few days after authorities arrested 20 officials and implicated Guatemala’s vice president in a tax-collection scam, nine people gathered on an April Sunday in the garden of a businesswoman in the capital.

They were an eclectic group, among them an environmental engineer, a law student, a guy who worked in his family’s elevator company. They had met on Facebook, and few had any organizing experience. But they were united in their outrage that the leaders of their impoverished Central American nation continued to enrich themselves at the public’s expense.

They wanted to organize a protest. But they wanted it to be different. No grand speeches or interviews with reporters, they decided. Everyone should carry a sign bearing a message. They would convene in the central plaza, sing the national anthem, and pick up the trash when the event finished. The online invitation created by Rafael Mora, a 23-year-old graphic designer, showed a massive crowd forming a circle.

In the middle it read: #RenunciaYa. Resign already.

They hoped a few people would show up. Thirty thousand came.

A man waits for a bus amid a flood of political campaign posters in Guatemala City, Saturday. Voters go to the polls Sunday for normally scheduled general elections, less than a week after Otto Perez Molina resigned as president. (Esteban Felix/AP)

That demonstration marked the birth of an extraordinary nationwide protest movement that helped force Guatemalan President Otto Pérez Molina from his colonial-era palace and into his current lodging in a military prison. The movement took energy from corruption probes by the attorney general’s office working with an unusual U.N. commission of investigators and law enforcement officers. Nineteen weeks after that first April protest, the president and vice president have been jailed, cabinet ministers have resigned, and dozens of people are under investigation in an elaborate fraud scheme involving public funds.

A confluence of factors brought the crisis to a head: maturing Guatemalan institutions with independent-minded prosecutors, international investigative support and protests led by the young and the middle class. Guatemala, still scarred from a brutal three-decade civil war and known as a place where powerful criminals almost always went free, is now being held up as an example for the region of how to fight public corruption and assert the rule of law. Even as voters prepared to vote on Sunday for a new president, many appeared stunned by what they had accomplished.

As one protest leader said, “The air in the country has changed.”

Organizing demonstrations had seemed risky. There was no lack of anger among the public. Vice President Roxana Baldetti was particularly reviled, seen as imperious and greedy. Even before she was named by prosecutors as the beneficiary in the kickback scheme that allowed companies to avoid customs taxes, she had been linked to a scandal in which the government paid $18 million to an unproven Israeli company to clean up a polluted lake with a watery substance that headlines derided as a “magic potion.”

But this was Guatemala, where 200,000 people had died in a civil war that ended in 1996 — most killed by the military. Citizens didn’t have a culture of protest. Students at San Carlos University, the largest public university in the country, were known for marching in balaclavas to hide their faces. As 22-year-old recent graduate Andres Quezada put it, “The biggest obstacle was fear.”

The parents of many of the organizers warned them not to get involved.

“They grew up in the ’80s in Guatemala, when going out to protest meant death,” said Gabriel Wer, a 33-year-old organizer.

That the first gathering passed peacefully helped inspire people to join subsequent protests, and they became a Saturday ritual in the plaza outside the presidential palace. There were also work stoppages and torch-light processions, but protesters adhered to nonviolent tactics. They didn’t break windows or burn cars; they offered flowers and pizza to police.

“Being peaceful is its own form of protest,” Quezada said.

By early May, Baldetti had resigned. At the next big protest, on May 16, students from wealthier private universities joined the San Carlos students. They arrived with their faces uncovered.

“It was raining so hard. We thought, ‘Everyone’s going to leave,’ ” said Glenda Lopez, 37,an environmental engineer. “Nobody moved from the plaza. Everybody stayed. People kept coming and coming. It was incredible.”

On the signs the protesters carried, one message stood out: “They messed with the wrong generation.”

Escalating investigations

As the demonstrations expanded, so did the investigations of high-level wrongdoing. Working with government prosecutors was a United Nations-backed body called the International Commission Against Impunity in Guatemala, known by its Spanish initials, CICIG. The body was established in 2007 in a last-ditch effort to save a failing state, whose institutions were so weak that murders almost never got solved.

Currently led by a Colombian lawyer and staffed by investigators from around the world, the group focuses on Guatemala’s highest-profile crimes. Cases used to rely heavily on witness testimony; now they began to be strengthened with scientific evidence, wiretaps and banking records. CICIG earned a reputation for being faithful to the evidence, wherever it led.

In 2010, CICIG solved the case of a high-profile Guatemalan lawyer, Rodrigo Rosenberg, who was shot to death in a killing many blamed on the government of Pérez Molina’s predecessor, Alvaro Colom. But CICIG’s investigation found that Rosenberg had hired hit men to attack him, in an elaborate form of protest suicide, a conclusion that vindicated the president.

The panel’s investigations also led to the arrests of high-level police officers for their involvement in prison murders. Last year, CICIG discovered a crime ring run from prison by a former army captain, Byron Lima Oliva. He had been convicted of the 1998 murder of Bishop Juan Jose Gerardi after the prelate published a lengthy report on civil war abuses that was highly critical of the military.

As the investigations mounted, Guatemalan officials have tried to hobble CICIG and shut it down. (Its mandate comes up for renewal every two years). As author David Grann described in a New Yorker article, police have tried to arrest CICIG witnesses and tailed the panel’s staff in unmarked cars.

“Every time there’s been a request to renew CICIG, you have people in Guatemala who say it shouldn’t exist, it’s run its course, or it’s impeding our own independent judicial system,” said Julissa Reynoso, a former deputy assistant secretary of state overseeing Central American affairs. “CICIG is still a necessary organization.”

The U.S. government, one of the largest donors to CICIG, paying $5 million a year, urged Pérez Molina to extend its mandate this year. The president, a former general, agreed to do so only after the April revelations of the customs-duties scam. That “forced the government’s hand,” said a senior U.S. State Department official, who requested anonymity because he was not authorized to speak publicly on the matter.

“I think for the first time, Guatemalans were shown how a criminal network, that appears to be at the highest level, works,” the official said. “They could hear people’s voices. They link that directly to the atrocious conditions people live in in this country. And across the board they said enough was enough.”

More scandals and protests

After Baldetti’s resignation, protest organizers were divided whether to push for Pérez Molina to step down, as some feared this would spark violence and civil unrest. The group calling itself Resign Already changed its name to Justice Already.

But new scandals emerged. The president's aides were implicated in a social security scam that prosecutors alleged left several dialysis patients dead. Cabinet ministers resigned. In August, Baldetti was arrested, but the president said in a national address that he was innocent, and refused to step down.

Several citizens’ groups planned a three-day protest for late August culminating in a work stoppage and giant demonstration. Small businesses first signed on, and larger chains such as Pollo Campero, a popular chicken restaurant, joined in. Employees whose offices stayed open sneaked out at lunchtime to join the crowds.

“You never had protests as massive as the ones we have seen,” said Adriana Beltran, a Guatemala expert at the Washington Office on Latin America. “A lot was driven by a new generation that through social media took to the streets, and that ignited and inspired others to join in.”

On Tuesday, the Congress voted overwhelmingly to strip Pérez Molina of his presidential immunity from prosecution. By that time he had become so widely discredited that his own party turned against him. The next night, he resigned, and by Thursday the former president sat before a judge, listening to recordings of his own voice discussing what prosecutors allege was his role in the bribery scheme.

Pérez Molina maintains his innocence. The case now hinges on whether the judge decides there is enough evidence to warrant putting him on trial.

The day he resigned, protesters waved flags in exultation.

“What happened in the plaza gave us a new spirit of citizenship,” Quezada said. “A hope that if we unite, we can do things. It was a great victory for the people.”