The Rev. Elizaphan Ntakirutimana, an ethnic Hutu who operated the church complex with regal authority, at first seemed to be a savior. He welcomed the Tutsis to the compound, a grassy campus containing a hospital and schools that had been a haven during past pogroms. He sent emissaries into rural areas to encourage Tutsi church employees to come out of hiding for sanctuary in Mugonero.

When the 8,000 refugees at the complex saw Mr. Ntakirutimana meeting with local Hutu political leaders, they assumed he was arranging their rescue from the Hutu-inspired mass murders that were engulfing the tiny nation.

It would prove to be a false sense of security, and fatally so.

Mr. Ntakirutimana was not what he seemed. Today, he stands accused of assisting in the murders of those he purported to save. Survivors now say they were betrayed by this man of the cloth, and they are demanding his return from the nation where he found sanctuary - the United States.

On April 16, 1994, witnesses now say, Mr. Ntakirutimana (pronounced In-TAW-key-ruti-mana) drove to the Mugonero complex in his beige Toyota Hilux pickup, leading a motorcade of Hutu soldiers and militia. The troops surrounded the grounds and began throwing grenades over the walls.

It was a Saturday, the Adventist Sabbath.

The killing continued for 11 hours. The Hutus of the interhamwe militia used guns, machetes and clubs studded with nails as they worked their way through acres of open ground where the men stayed. Some victims fought back with stones. Those who did not fall retreated indoors.

Then the killers moved into the redbrick offices, schoolrooms, dormitories and houses where the women and children took refuge. They killed in the church. They killed in the hospital.

``My 3-year-old son begged them not to kill him, begging their pardon for being Tutsi and saying that he would no longer be Tutsi," survivor Lydia Nirara recalled in written testimony a year later. Her son and seven of her 11 other children were killed.

When the slaughter at last ended at 10 p.m., only a few among the 8,000 Tutsis survived - many by hiding under corpses heaped in the hospital's surgical wing. They slipped out at night and took refuge in the surrounding mountains.

Later the survivors would tell their stories. Many say Mr. Ntakirutimana supervised as the killing took place. A few said he called out a list of names of those who should die. Many said that in the days after the slaughter he helped hunt for survivors in the mountains. One man says he saw the pastor fire a gun.

Although the survivors' details vary, they all agree that Mr. Ntakirutimana, head of the Adventist church in the western Kibuye prefecture, was an active and willing participant in the genocide - that he betrayed thousands of people who had entrusted him with their lives.

``What gives me grief is that after the pastor had all these people killed, he didn't even see to burying them, including his fellow pastors," Nirara said in her testimony. ``They lay outside for two weeks, eaten by dogs and crows."

In September 1996, the pastor was one of the first people indicted by the International Criminal Tribunal for Rwanda, the U.N. body that is judging war crimes committed during the 1994 genocide. His son Gerard, a physician, also was indicted.

But Pastor Ntakirutimana will not appear in the tribunal's courtroom in Arusha, Tanzania, any time soon. He is the only Rwandan wanted for genocide who is being held in custody in the United States. So far, he has successfully fought extradition.

``We were grateful the Americans arrested him," said Samuel Ndagijimana, 32, a surviving health worker at the hospital who lost more than two dozen relatives in the genocide. ``We felt some relief knowing he was in jail, but we don't understand why he has not been sent over for trial."

Mr. Ntakirutimana, 74, was arrested in 1996 in Laredo, Texas, where his son Eliel is an anesthesiologist. The arrest came in response to an extradition request from the tribunal. He was charged with genocide and crimes against humanity.

He and his family have mounted a vigorous defense, arguing that the U.S. law allowing extradition of suspects to the war-crimes tribunal is illegal.

A federal magistrate ruled in December that the law allowing extraditions to international tribunals investigating war crimes in Rwanda and the former Yugoslavia was unconstitutional because there is no U.S. treaty with either tribunal. He ordered Mr. Ntakirutimana released.

Acting on a new extradition request from the tribunal, the U.S. Justice Department rearrested Mr. Ntakirutimana in February. A federal judge last month approved the extradition request, and Mr. Ntakirutimana is in jail pending an appeal of that ruling.

His case has become the focal point for Americans reluctant to concede judicial authority to an international tribunal.

``No nation, or person, should be subject to judgment and punishment by a court created by a power entirely foreign to it," former U.S. Attorney General Ramsey Clark argued in court last year on behalf of Mr. Ntakirutimana.

Mr. Ntakirutimana's supporters argue that the case against the pastor has been fabricated by the Tutsi government that came into power after the genocide. They say the government is bent on revenge against prominent Hutus.

What happened in Rwanda remains incomprehensible. It was as though a communal psychosis overtook the nation during those three months in 1994 when the majority Hutus were egged on by extremists in the government to exterminate the Tutsis, people historically regarded as the Hutus' oppressors.

``It is a sad story for a pastor who preached love and peace to violate the peace of others, but it wasn't just our church where this was happening," said Amon Rugelinyange, president of the Seventh-Day Adventist Church in Rwanda, who lost his wife, three children and eight grandchildren in the genocide.

Tensions between Hutus and Tutsis were rising across Rwanda in early 1994, but few imagined the horror about to unfold.

In Kibuye prefecture in western Rwanda, a breathtaking land marked by sharp hills that fall dramatically into Lake Kivu, anti-Tutsi sentiment slowly rose to the surface. Kibuye historically had one of Rwanda's highest concentrations of Tutsis because the land is better suited for herding cattle, the traditional Tutsi occupation.

The strains were also felt at Mugonero, where the Seventh-Day Adventist hospital complex was built 70 years ago by American missionaries on a pleasant grassy hill overlooking Lake Kivu.

In a nation where most people are Roman Catholic, the Seventh-Day Adventists always seemed to identify more closely with their church than their ethnic group. The traditional rivalries between the lanky Tutsis and the stouter Hutus did not seem to apply.

Mr. Ntakirutimana was well-known in western Rwanda. As the head of the Adventist church in Kibuye prefecture, he commanded a position of authority and some wealth. His seven children were well-educated. Nobody could recall ever hearing Elizaphan Ntakirutimana express anti-Tutsi sentiments in public.

But Mr. Ntakirutimana was not regarded as a man of the people. In a place like Kibuye, where hardly anyone owns a vehicle, the measure of a man's character is whether he gives people a lift. The pastor never stopped his pickup for hitchhikers, residents recalled.

Ndagijimana, the surviving hospital worker, said the pastor's son once offered him a ride from the provincial capital. But Gerard Ntakirutimana asked his rider to get out of the pickup before they arrived at the hospital so that his father would not see he was giving rides to employees.

``It was known that they were elitist," Ndagijimana said. ``But we didn't know they had these ethnic beliefs."

Isaac Ndwaniye certainly had no inkling that the pastor was anti-Tutsi.

Ndwaniye, a Tutsi, was director of publications for the church in Mugonero. He worked in the same office as the pastor. The rising tension in Mugonero in early 1994 was enough of a concern that when Ndwaniye was summoned to the capital, Kigali, on business on April 5, he made a point to ask the pastor to take care of his wife and nine children.

``I asked him to keep watch over my family," said Ndwaniye, who is now director of publications at the church's national headquarters. ``I asked him that personally."

The day after Ndwaniye left for Kigali, the genocide began. He lost his entire family at the compound.

Rwanda's genocide began on April 6 after a missile fired from the swamps near Kigali's airport downed the plane of President Juvenal Habyarimana, a Hutu who had negotiated a power-sharing agreement with Tutsi rebels, enraging Hutu extremists.

Within hours, Hutu radio blamed the assassination on Tutsis and encouraged the populace to wipe out the ``cockroaches" - their term for Tutsis.

By the next day in Mugonero, bands of Hutu militiamen and activists in extremist political parties began burning and looting Tutsi homes.

The terrified Tutsis fled to the hospital, the one place that had provided a safe haven during previous anti-Tutsi massacres in 1959 and 1973, when the hospital was operated by American missionaries.

Protected by police, the refugees soon swelled beyond the capacity of the hospital buildings. The men camped on the lawns while women and children stayed indoors. They paid the gendarmes guarding the compound to bring them food and quickly developed a warm bond with their protectors.

Mr. Ntakirutimana appeared to be sympathetic, too. When he heard the director of the Adventist secondary school, Jean Nkuranga, was hiding in the countryside, he sent a message to urge him to come to the safety of the Mugonero compound. He came, and there he later died.

As the days wore on, injured Tutsis arrived from the countryside with machete cuts, gunshot wounds, and hideous stories about the extent of the bloodletting. Gerard Ntakirutimana treated the patients at the hospital.

But not everything was secure in the compound.

The refugees noticed that the pastor and his son met frequently with local political and business leaders at the hospital office. ``We thought those meetings were for our protection, that they were discussing ways to save us," Ndagijimana, the hospital worker, said.

A few days later, Gerard Ntakirutimana ordered hospital workers to stop treating wounded Tutsis, saying it was a waste of medicine, survivors said. And then hospital officials told Hutu workers to leave the complex.

On April 15, the police commander met with political leaders. ``When he returned, he told the people that he no longer had the authority to protect them, and that they should die," recalled Bimenyimana Manesse, an orderly at the complex. ``He said the government decided this."

Knowing they were doomed, the 60 Adventist pastors who had sought refuge at the church complex wrote an appeal to the local mayor, Charles Sindikubwabo, whose father was an Adventist pastor.

They wrote a second letter asking the Rev. Ntakirutimana to intervene. Mr. Ntakirutimana sent a message saying there was nothing he could do.

The pastor was not seen until the next day, when survivors say he led the procession of trucks containing militia and national police. Most survivors say they did not hear the pastor say anything. Elie Gashi, 37, a janitor who still lives in Mugonero, said the elder Ntakirutimana came and told the Tutsis about to be killed: ``You die like men, not like children."

Another witness said the pastor read a list of names of Tutsis believed to be a special threat, such as intellectuals.

``He himself read out a list over the loudspeaker of the names of the people to be killed," Esdras Nzamwita testified in 1995. ``I heard him read that list, but I did not see him kill anyone himself."

Without weapons, there was little the Tutsis could do to fight back. Some threw stones. Most attempted to herd their families together.

After the massacre at Mugonero, the survivors fled. Some sought refuge at night in an Adventist church in nearby Murambi, but they said Mr. Ntakirutimana and his son ordered workers to remove the roof from the church so the shelter would be uninhabitable.

About 50,000 people who escaped from villages in the region retreated to the mountain named Bisesero, now famous in Rwandan lore as one of the few places where Tutsis resisted the onslaught.

Almost every day Hutu militia would come to the mountain to hunt the Tutsis living in the woods. Witnesses said the pastor and his son showed up as well.

Several said Gerard Ntakirutimana was seen at Bisesero, wearing short pants and shooting a gun. Others said the doctor tried to lure resisters out of the woods by sending a false message that American soldiers had come to protect them.

Pascal Bayingana, 39, a farmer who lost his wife and one child at the complex, said Mr. Ntakirutimana shot his remaining three children during the two-month siege at Bisesero.

``I saw him shoot my children," Bayingana said. He is the only person who says he saw the pastor with a weapon.

When the French army arrived at Bisesero near the end of June, the soldiers found only about a thousand Tutsis alive.

The Hutus who engineered the genocide, meanwhile, fled Rwanda as the rebel Tutsis swept into power in late June and early July. Mr. Ntakirutimana was among the hundreds of thousands who escaped.

Many Hutus who fled to avoid retribution settled in camps in neighboring Zaire, now called Congo. Mr. Ntakirutimana made his way to Zambia, where his son Eliel had arranged for a U.S. visa; the pastor had not yet been indicted by the tribunal. From there, he traveled to his son's home in Texas.

Gerard Ntakirutimana fled to Ivory Coast. He was arrested at the request of the tribunal and transferred to Tanzania. He is among 31 prisoners in Arusha, Tanzania, awaiting trial.

After the genocide, international investigators descended on Rwanda. Alison Des Forges, an investigator with Human Rights Watch-Africa in New York, arrived at Seventh-Day Adventist headquarters in Kigali in 1994 to interview survivors of another church massacre. ``People spontaneously mentioned Ntakirutimana," she said.

The Rev. Ntakirutimana has declined interviews, but he wrote a letter last year to the president of the Texas Conference of the Seventh-Day Adventists in which he denied inviting anybody to kill the people assembled at Mugonero.

Mr. Ntakirutimana said that on the morning of the Mugonero massacre he asked a military mayor to protect church families. Then he said he and his son Gerard loaded their families into two pickups and drove away, not returning for 11 days.

After the genocide, the new Tutsi-led government built a wall and a memorial around one of the mass graves inside the church complex, where bodies are buried beneath a bed of lilies. The other grave, where corpses were dumped into a latrine trench, is unmarked.

Today Mugonero appears peaceful. The buildings have been rebuilt with new doors and windows to replace those stolen by looters. The bullet holes have been patched and painted.

The pale yellow church with concrete bench seats where many died is no longer used for services. It has become a silent memorial, containing four pine coffins draped with white linen marked with black crosses.

In a country as tiny as Rwanda, few people have secrets. There were 250,000 Tutsis in Kibuye prefecture before the genocide. Only about 8,000 remain. They know who did the killing.

Manesse, the hospital employee, is uncomfortable working at the place where his loved ones died along with so many others. He knows that not so long ago some of the patients and some of his neighbors would liked to have seen him dead.

``If I could find another means to make a living, I wouldn't work here," he said. ``Sometimes I treat people who I think were involved in the genocide, and I have to do it as a medical worker. But I don't like it."