Not only has leading presidential candidate Alfonso Portillo admitted to fatally shooting two men--in what he says was self-defense--during a brawl in Mexico 17 years ago, but he has come close to boasting about it in TV campaign commercials.

It is also no secret that the opposition party he represents, the Guatemalan Republican Front (FRG), is headed by a onetime military coup leader, Efrain Rios Montt, whom human rights groups have accused of genocide in the early 1980s. An estimated 200,000 people lost their lives or disappeared during a 36-year civil conflict.

But as Guatemalans prepare to vote Sunday in the country's first presidential election since the conflict ended in 1996, polls make Portillo the clear front-runner, riding a wave of popularity that reflects the problems, frustrations and complexities the country is grappling with in the aftermath of Central America's longest and deadliest civil conflict.

Portillo, 48, has waged a populist law-and-order campaign that has attracted the support of many Guatemalans disenchanted with a government they consider elite, corrupt and unable, if not unwilling, to deliver the social and economic dividends they hoped peace would bring.

In a country where the ravages of war have given way to distressing levels of more common violence--forcing the government to rush recruits of the new civilian national police force into duty with minimal training--Portillo has deftly used the Mexico shooting episode to portray himself as a steely crusader against lawlessness.

He has thus tapped into Guatemalans' widespread concerns about worsening public safety and a justice system that remains dysfunctional because of corruption and incompetence. In one Portillo TV ad, which proudly alludes to the Mexico incident, an announcer says, "A man who can defend his own life can defend yours."

"There is so much chaos and crime that I think someone like Portillo is needed to bring order and more safety for us so we do not have to sleep in fear," said Carmen Sequen, 30, a Mayan bread vendor in the town of San Juan Sacatepequez just outside this capital.

Manfredo Marroquin, a political analyst at Citizen Action, a Guatemala City think tank, said, "Here, impunity is the law. Why should people judge Portillo? Here, only fools go to jail."

In September, Portillo admitted that in 1982 he gunned down two men during a confrontation that began at a street party in the Mexican state of Guerrero. Portillo, who was a law professor there at the time, said he fled because he feared he would be prosecuted unjustly. A judge closed the case in 1995.

Portillo's candidacy has also been boosted by those who are nostalgic for the era of Rios Montt's rule during which he conducted crackdowns on common crime and corruption while giving short shrift to human rights. It was also during that period that Rios Montt carried out his "scorched earth" counterinsurgency campaign to eliminate support for leftist rebels in the countryside, targeting indigenous people in particular.

Sunday's election comes at a time of disillusionment and concern over the failure of the government of President Alvaro Arzu to implement key reforms tied to the three-year-old peace accords that were aimed at rebuilding Guatemala and addressing the social, political and economic problems that fueled the war.

For instance, officials do not expect to meet next year's deadline for revising the tax structure to bring collection totals to 12 percent of the gross domestic product, from the current 9.2 percent, to help pay for increased social spending. A new target date has been set for 2002.

A recent series of polls gave Portillo around 45 percent of the vote, about 12 percent ahead of Oscar Berger, a former mayor of Guatemala City and the candidate for the ruling National Advancement Party (PAN). Portillo put in a strong showing four years ago against Arzu, who is constitutionally barred from seeking reelection.

The election is also the first in which former guerrillas are running as a political party. But polls show that Alvaro Colom, an industrial engineer who is the candidate for the leftist New Nation Alliance coalition, which includes the rebels, is lagging a distant third. To avoid a Dec. 26 runoff, one of the 11 presidential candidates must win an outright majority.

Rios Montt, 74, who came to power in a 1982 military coup, is running for a congressional seat with the FRG and is likely to prevail. He would be in position to become the chamber's next president.

The political debate about the future of Guatemala's peace has taken place amid growing calls from war victims' groups to prosecute the many military officers believed to have committed wartime crimes. Hugh Byrne, senior associate for Guatemala at the Washington Office on Latin America, said of the FRG, "Can a party so closely tied to major human rights violations in the past seriously address the issue of impunity? It is almost impossible to imagine."

While Portillo openly sympathized with Marxist rebels during the war, he and Rios Montt have found common ground in a platform that criticizes the government and the PAN as a club of oligarchs who heightened a "class confrontation." He has also broadly pledged to promote peace and jobs for Guatemalans while doing away with the monopolies and privileges of the few who control the country's wealth.

In a recent interview, Portillo, who identifies himself as a social democrat, shied away from advocating a leftist economic model. "I have rejected the intervention of the state in the economy, the class struggle, the dictatorship of the proletariat. That was an era of romanticism in my life," he said.

But much of Guatemala's future hinges on the evolution of the peace process, which suffered a major setback last May when voters rejected a complex package of constitutional reforms that would have, among other things, officially recognized the legal and cultural rights of indigenous people, who make up a majority of the population, and limited the army's broad functions.

CAPTION: Alfonso Portillo, who admits he killed two men in a brawl 17 years ago, greets voters while campaigning in the eastern city Zacapa for today's presidential election.

CAPTION: Oscar Berger, the ruling party candidate, picks up a child while campaigning in Guanagazapa, south of the capital. Berger was running second in opinion polls.