FOR 34 PEOPLE scattered around the world, May 30, 1978, was a dramatic and even emotional day. On the top floor of the Brazilian federal police headquarters in Sao Paulo, two men who had last seen each other 35 years previously in war-ravaged eastern Poland were brought in from opposite sides of the room. It was a staged confrontation.

Both were postwar refugees from Europe. The elderly one, Gustav Wagner, a former Austrian, was tall, gray-haired but very fit. The younger, Stanislaw Szmajzner, slight and balding, was born in Poland.

"Hello, Gusti," called Szmajzner. Wagner was momentarily caught unaware, then smiled: "You should be grateful to me. I saved you from the gas chambers.

Not gassing Szmajzner cost Wagner some of his freedom and satisfied some of those who survived his daily tortures that, at long last, their tormentor should feel some suffering. For a year, he lay on a bed in a cell in a psychiatric hospital near Brasilia, guarded round the clock, awaiting a decision by the Brazilian Supreme Court. But late in June, the court denied petitions from West Germany, Israel, Austria and Poland seeking his extradition.

Gustav Franz Wagner was the deputy commandant of the Sobibor extermination camp in eastern Poland. It was not a conventional concentration camp, because there was no work for those who arrived.

Sobibor was a killing center. Its production line was as sophisticated as a complex modern factory. In just 15 months, 250,000 men, women and children stepped off the train in the morning, were gassed by lunchtime and their corpses burnt before dawn the next day. By then their luggage had been sorted and packed for shipment to Germany. The victims were gassed by the carbon monoxide fumes of a captured Russian tank.

Of the quarter of a million who came, just 34 survived. Wagner's role in that assembly line was crucial. He had arrived in March 1942. Handpicked for the task, his initial job was to build the camp -- to erect the buildings and the wire fences, which were later electrified, dig the anti-escape trenches, lay the minefields, construct the gas chambers and organize the laying of a small railway siding so that the trains could pull off the main line and discharge their cargoes.

Sobibor was one of four locations chosen under "Operation Reinhardt" to overcome the inefficiency of mass shootings. The other were Chlemno, Belzec and Treblinka. It was their accessibility to the rail network, yet their remoteness from populations, which made them ideal for the architects of the Final Solution.

Wagner watched as thousands of people jumped and fell out of cattle trucks and were often whipped on to the parade ground. Sometimes he selected a few to work on camp maintenance in Camp One and sent the rest to Camp Three, ostensibly for a shower, in fact to be gassed.

Today, Wagner says he was depressed seeing people going to be gassed, but there was nothing he could do to help any of them: "I didn't think it was right. One saw these people exterminated who were really innocent, but there was nothing I could do. The maxim was: the fuehrer's orders must be carried out."

Wagner insists that it was not possible to resign. "They would have shot us. We were under oath, involved in top secret Reich work." In fact, many investigations have shown that the few SS men who did refuse to continue were merely transferred to other work.

More alarming is how Wagner describes his lack of feelings at the end of a day's work: "I had no feelings, although at the beginning I did. It just became another job. In the evenings we never discussed our work, but just drank and played cards." When pressed as to how one could daily kill thousands and just not talk about it, Wagner's reply is simple: "We had a feeling that if we lost the war we would be saddled with the consequences." But even if Wagner is aware of his wrong doings, he doesn't see himself as a criminal. "I feel," he says, "like an ordinary man, no different from others."

It was those not sent to Camp Three, those who worked on camp maintenance and sorting the luggage of those who had perished into various piles -- toothbrushes on one side, combs on another; children's dresses and toys separate from women's dresses and shoes -- who are today's witnesses to Wagner's brutalities.

They describe the extraordinarily restless, animal-like sadist who, according to Esther Raab, "came into the warehouse, with his two thumbs in his pockets -- you knew he needed blood. He had to kill somebody, even two or three -- whoever came in front of him. He'd go around and pick his people. Like a drunk that needs drink, he had to have blood." It was after he had seen blood, after he had beaten someone to death, according to Sam Lerer, now a New York cab driver, that "his restless nail-biting would stop. He became very calm and happy. He would come and chat to people."

Wagner, according to the survivors, had many methods of killing Jews. Says Thomas Blatt, "He didn't kill the same way as the other Germans. He didn't shoot, he tortured. He used an ax, a shovel, whip, even his bare hands. I saw him pick up a shovel and simply split a man's head in two. He didn't need a reason for doing it. Perhaps the man was moving too slow. But when he killed he smiled. Murdering was his pleasure -- you could see it in his face. He didn't consider it a duty, it was more his private matter."

Lerer saw Wagner use an ax handle to beat to death a father and son standing next to each other. "It took just a few minutes. He and another SS man just kept on hitting them. The sound of the cries of these two men sounded like wild animals." For Blatt, who was once given 50 lashes by Wagner for a triviality, even the mention of Wagner's name is sufficient "to make my stomach turn and my heart beat stronger."

Wagner's gun apparently was reserved for special occasions. "Once," says Esther Raab, "he was looking through a window, to check as we sorted the suitcases. He saw a boy steal a can of sardines. He grabbed the boy and called us all out, put us in a half-circle and shot him right in front of us. Then he said that's what would happen to every one of us if we touched anything."

Wagner, not unnaturally, denies that he ever attacked anyone. In fact, he insists that he wanted to protect the inmates: "There was no reason to hurt them, they just obeyed. And we knew the way they were going to go was hard enough. No need to add beatings." Nor, he says, did he ever kill anyone. "It was against the rules."

Most people can understand someone lying to save his neck. But the survivors cannot. "At least," says Lerer, "he could have the guts, the dignity, to admit to what he did and that he dislikes the Jews. Many of the other German SS in the camp didn't behave like him. Other Germans were even afraid of him, including his own brother-in-law [who also worked at Sobibor]. It's plain stupid to say he was just obeying orders." Wagner now claims he was never anti-Semitic.

At this time it is difficult to be certain whether Wagner's enthusiastic sadism was the product of a certifiable psychopath or an overly convinced Nazi. Even today he does not deny that he considers Hitler to have been "an extraordinary man." "No one can be blamed," he says, "that everything went wrong." He does not mean the "wrong" to be the events at Sobibor, but that Germany lost the war.

His denials about his ruthless murders are plainly worthless. But one denial has a degree of truth, the more so because some of the survivors accept it as showing his blind adherence to Hitler's theories of a "master race."

The quarter of a million that came to Sobibor brought their life savings, often hidden in their luggage, sometimes even inside their bodies. Huge amounts of money, gold and precious stones were collected and itemized daily for the SS's own balance sheets. A lot of the valuables were stolen by the Ukranian guards and the Germans. But Wagner denies he ever stole any. "It's against my deepest convictions to make my fortune out of the misfortune of others. It's against my principles." He cannot explain why it was wrong to take money from these people, but not wrong to gas them.

Wagner was born in Vienna in 1911. He claims that he joined the then illegal Nazi Party in 1931 because, although a professional soldier, he was attracted by its program and the ideal of the unity of German-speaking people. "My friends joined and so did professors, doctors and businessmen." He was soon arrested for daubing swastikas and putting up posters. In 1934, to enable him to escape further arrest, the party smuggled him over the border into Germany. He reported to a local SA detachment and was assigned to guard duty outside a camp. In 1940, by then a member of the SS, Wagner claims that he was advised that if he reported to Tiergartenstrasse 4 in Berlin he would get an office job that would keep him away from the front.

Tiergartenstrasse was the headquarters for the Foundation for Institutional Care, the center for planning the "mercy killing" of the mentally and physically handicapped. Although told that this was top secret Reich work, Wagner, surprisingly, does not now claim that he was either blackmailed or forced to join. Days later, Wagner arrived at Schloss Hartheim, a pretty castle near Linz.

This was one of six pseudo-hospitals which were in fact schools for murderers -- laboratories for both the scientific and practical problems of mass extermination. Desolate families were convinced by doctors that there was a chance of a remedy for their relations and were asked to sign an entrustment. Some weeks later they would receive a long, tearful letter of condolence and, occasionally, the offer of the ashes. In fact, literally "under medical supervision," batches of the mentally sick were gassed by carbon monoxide fumes or given letal injections.

Wagner claims that he only discovered the truth after he arrived. "I worked in the office, doing the paperwork. I discovered what they were doing, but that was the doctors' decision. I didn't feel good but I was told that I was sworn to silence." The image of the reluctant and obedient servant of the state unwittingly deceived cannot be contemptuously brushed aside. But it is Wagner's own description of his reactionat the time to the murder of innocents which belies his tale. "I didn't think anything about what was happening. I didn't see how and when they were killed. Everyone knew it wasn't a pleasant business, but it was a matter for the doctors . . . We never discussed it. We just played cards in evening. I mean there were so many young girls and others . . . lots of young, healthy people, and we just didn't talk about it."

Clearly, Wagner satisfied the architects of the Final Solution, because in March 1942 he was handpicked on the basis of his Hartheim record to build the Sobibor camp. It is a testament to Wagner's authority that all the survivors describe his shrewdness and intelligence, his ability to "smell out" anything suspicious. Consequently, the inmates planned the final attempt to revolt and break out to coincide with Wagner's vacation.

At 4 p.m. on Oct. 14, the revolt started. A few German officers had been killed by axes inside buildings and their guns stolen. The attempt to storm the armory failed. At first, a few, then more of the 600 inmate-workers rushed the electrified fences. They were either killed at the perimeter or in the minefields. Those who came later climbed and stepped on their bodies. Within an hour, it was all over. Probably not more than 100 escaped.

On his return, Wagner was ordered to close the camp. Systematically, the SS destroyed every building, removed the minefields and tore down the barbed wire. Finally, hundreds of sapling pines were planted. It was a professional touch symbolizing the deception of the entire program. All that remains today is a memorial hill built by the Poles. Inside it are ashes and a few bones scraped up from the earth. Among them are the remains of 200 teenage girls specially shipped in on the day Heinrich Himmler visited the camp. The camp commander put on a special show -- gassing for the dignitary.

Wagner ended the war in an American POW camp. He produced some false papers proving that he had been an army motorcyclist, and three weeks later was driven to Salzburg and released. In 1946, his name appeared on the United Nations list of war criminals. But the Allies had failed to organize any realistic program for the investigation of war crimes.

He decided, nevertheless, in 1948, to escape from Europe. While he was working on a building site in Graz, Franz Stangl, a friend and former commandant of Treblinka, passed by. Stangl had escaped from prison and, aided by Odessa, an undergound Nazi escape group, was on the Vatican route. Wagner joined him. On arrival in Rome, they went to the priest confessor to the German Catholic community, Bishop Alois Hudal. Pope Pius XII had been sympathetic to the Third Reich, and many fleeing SS men, including Adolf Eichmann, benefited from the Vatican's help after Germany's defeat.

Hudal arranged Red Cross passports for the two men and, three weeks later, they sailed for Beirut. But an offer to train the Syrian army disappeared and, in 1952, Wagner got a visa for Brazil. He arrived under his own name. Neither then nor in the next 26 years did the Brazilian police ever inquire into his past. He married a Brazilian woman (who has since died), and built a solid Bavarian-style house in the isolated wooded hills outside Sao Paulo.

Back in Germany, some of the former SS officers at Sobibor were caught and tried. For each trial, the handful of survivors would be flown in from around the world to testify against their former tormentors. Questioned about the whereabouts of Wagner, the German prosecutors insisted that he was beyond their grasp, living in Egypt. The first break came in 1967. Simon Wiesenthal, the famed Nazi-hunter, traced and organized the arrest of Stangl in Brazil. Stangl was extradited and tried in Duesseldorf. Sentenced to life, he died soon after, but had already betrayed Wagner's whereabouts.

However, requests by Wiesenthal to the Brazilian police and even the employment of private agents failed to locate Wagner. He had allegedly gone underground. Wiesenthal suspects that Wagner probably was protected. Wiesenthal decided to play a waiting game, hoping to lull Wagner into a false sense of security."I decided to be quiet. Over 10 years, in all the interviews, I spoke about Mengele and others, but never mentioned Wagner." His patience was not rewarded. The only solution, he decided, was to play a trick.

Flying from New York to Vienna in early 1978, Wiesenthal was reading through news clippings sent to him by his agents throughout the world. A Brazilian newspaper had a photo next to a regular news story about a group who had celebrated Hitler's birthday in a village north of Sao Paulo.

Some weeks later, through an arrangement with a friendly Brazilian journalist, Wiesenthal announced that a dark-haired man with big ears appearing in the photo was Gustav Wagner. The article quoted Wagner's birth date, ID card number and a survey of his wartime career. In the sensation that ensued, "big ears" in the original photo was identified and swiftly eliminated. But the real Wagner was forced into the open -- initially to deny the accusations, but then to insist that he was just a minor official.

Wiesenthal's reaction to the arrest was surprisingly muted: "I cannot say I'm happy. I always think about all those people who didn't survive to see Wagner in jail. What is important is that 37 years after the crime, 10,000 miles from the scene, a murderer has been caught. It is a warning for the murderers of tomorrow."

For Esther Raab, the ideal punishment would be for Wagner to be put in a concentration camp. Lerer seriously states that he would personally like to torture Wagner. Blatt, who since the war has traveled the world obsessively collecting memorabilia on Sobibor, is less emotional: "We all dreamed that if we survived, we'd cut him slowly to pieces and make him suffer a slow death. But if we did that today, we'd go down to his level. So I'd simply put him in jail."

Wagner, now 68, says, "I thoroughly enjoyed Brazil, and didn't think about the past."

Esther Raab has thought of little else: "It never leaves me. I dream about it, even scream at night. He's always chasing me, wants to catch me to put me in the concentration camp. I see children's heads smashed against wagons, people killed in front of me, people being tortured . . . it has left me so that I can never be happy and I cannot help it.' CAPTION: Picture 1, Gustav Franz Wagner. Copyright (c) 1979, Tom Bower; Picture 2, Death camp survivor Stanislaw Szmajzner and Gustav Wagner meet in Brazil in 1978. AP