BY KAREN L. SHAW AND GLENN GARVIN

 GUATEMALA CITY -- Climaxing a month of religious processions and Christmas
 parties, Guatemalans will almost certainly choose an admitted killer for their
 president when they go to the polls Sunday in their first election since the end of
 a 36-year civil war.

 Opposition candidate Alfonso Portillo, 48, who fell just a few thousand votes short
 of winning the presidency outright in the first round of voting last month, is a huge
 favorite in the runoff.

 Several polls -- including one released last week by the Costa Rican firm Borge
 and Associates -- show Portillo with a lead of 35 percentage points or more over
 his only opponent, former Guatemala City Mayor Oscar Berger.

 ``The results of the Borge poll show that Sunday we will demolish them, and I will
 be the next president,'' Portillo said.

 Less partisan analysts agree. ``Statistically, Berger would need a miracle to win,''
 said Indian activist and political columnist Estuardo Zepeta.

 Portillo was running a lackluster second to Berger earlier in the year, before he
 admitted -- some say boasted -- that he killed two law professors in a 1982 bar
 brawl while living in exile in Mexico. Soon after that, he zoomed past Berger in the
 polls and has never looked back.

 The two victims in 1982 were Portillo's rivals for the deanship of the law school
 where he was teaching. He says he killed them in self-defense; the victims'
 families say they were unarmed. A warrant was issued for Portillo's arrest, but
 police never caught him and the statute of limitations has long since expired.

 AWKWARD SITUATIONS

 Mexican diplomats look uncomfortable when asked how they'll get along with a
 president who killed two of their countrymen, but ultimately answer that their
 relationship is with the nation of Guatemala, not any particular president.

 But a real diplomatic contretemps may develop over the founder of Portillo's
 Guatemalan Republican Front (FRG) party, former Gen. Efrain Rios Montt, who is
 expected to be president of the next Congress.

 When he was running Guatemala as a military strongman in the early 1980s,
 Rios Montt directed a scorched-earth campaign against Marxist guerrillas that
 resulted in the execution of thousands of civilians. At the time, Portillo was a
 guerrilla sympathizer who was forced into exile.

 Now an effort is under way to have Rios Montt arrested and extradited to Spain to
 face trial over those killings.

 Rigoberta Menchu, an Indian activist who won the 1992 Nobel Peace Prize, has
 filed charges against Rios Montt and four former high-ranking officials in his
 regime.

 Menchu filed the charges before the same Spanish judge whose efforts to win the
 extradition of former Chilean President Augusto Pinochet have resulted in
 Pinochet's arrest and detention in England.

 Rios Montt has dismissed the charges as a political publicity stunt and has said
 he will not be afraid to travel outside Guatemala. But the criminal charges appear
 to have heightened tensions within the FRG, between forces loyal to Rios Montt
 and those who joined the party with Portillo.

 EARLY SQUABBLING

 Until recently, the seemingly strange alliance between a former rightist general
 and a former leftist guerrilla sympathizer united by their populism had been
 working rather well. But with victory near, supporters of the two men have been
 squabbling over the spoils of the election as well as old political feuds dating to
 the civil war. Portillo even snubbed the FRG's Christmas party, sending his wife
 instead.

 ``It's pretty amazing to see a winning party so divided, so publicly, before it even
 takes office,'' Zepeta observed.

 Whatever political fireworks may come after the election, few are expected
 Sunday. Though accusations of fraud and incompetence flew after the November
 voting and led many diplomats to fear that the runoff election could turn violent,
 Portillo's huge lead -- coupled with the election's timing on the day after
 Christmas -- have lowered the tension.

 ``The date, the time, makes it very difficult for the people to vote,'' said Aura
 Marina de Leal, the 47-year-old director of a Spanish language school. ``The most
 important thing is that the people really return to vote.''