The killers came on a spring afternoon, as many as 7,000 men crowding down the narrow lane towards Nyarubuye church.
Nyarubuye church was the scene of a notorious massacre
Nine days earlier the plane carrying Rwanda's Hutu President, Juvenal Habyirimana, had been shot down flying into the capital Kigali.
Within hours the slaughter of members of the Tutsi minority as well as moderate Hutus had begun.
Among the killers marching to the church were Gitera Rwamuhuzi and his friend Silas Ngendahimana.
The Tutsis, including Flora Mukampore, had fled to the church believing they would be safe.
The local Mayor, Sylvestre Gacumbitsi, gave orders to the police to shoot, and then the peasants moved in to kill - hacking, slashing and bludgeoning their neighbours to death. Between five and ten thousand Tutsis were killed.
When I reached the scene weeks later the rotting bodies lay twisted terribly, skulls smashed open, faces frozen in the last terrible expression of violent death. How could men do this, I asked myself.
It is a question that has haunted me for a decade. Ten years after the slaughter I met some of the killers. Most are in jail but will soon be released under the government's Gacaca programme after confessing their crimes and apologising.
Gitera Rwamuhuzi is the most confident of his group and the natural leader. He smiled and shook my hand warmly.
He is an intelligent, complex man - and a ruthless killer. Before the genocide he was a local criminal gang enforcer and is said to have killed as many as 100 people, with his gang responsible for 300 deaths.
He has confessed only to three murders. "Whoever is telling you that story is exaggerating to try to make my name look bad," he says.
Gitera describes lying on the ground at Nyarubuye while the soldiers opened fire. He saw a Tutsi man trying to escape from the church and ran over and struck him on the head, killing him.
He blames Satan, a common theme among the prisoners. Responsibility is passed out of their hands to some supernatural force. There are no guilty men, only victims of dark forces.
But he also believed he was going to be killed by the Tutsis. "We thought that if they had managed to kill the head of state how were we ordinary people going to survive?" he says.
Gitera describes killing his next door neighbours.
"They looked traumatised. They were people who had lost weight because they had not eaten for days. After killing the mother the toddler fell by her side," he says, crying.
Cyasa Habimana refuses to be photographed with the others, believing he is a man of greater substance. He also reads from his diaries, believing they justify him.
The Interahamwe militia group leader says he was a tool of more powerful men. He is cunning but with no imagination, an ex-army sergeant with a reputation as a hard man and a good organiser. He was persuaded to train the Interahamwe by an army colonel.
Cyasa does not blame the devil. He says the colonel gave him a new set of tyres for his truck and threatened to kill him if he did not comply.
He says he was not at Nyarubuye but was involved in attacks elsewhere in the area in which thousands of Tutsis died.
To the survivors, Cyasa was a monster, devoid of pity. He is now under sentence of death.
Silas Ngendahimana was tending his crops of sorghum when he heard that the president's plane had been shot down.
At Nyarubuye church Silas carried a large impiri, a club studded with nails which he used to beat a Tutsi woman to death.
"You have to understand mercy wasn't part of the deal. The government had given them up to us to be killed," he says.
He points to his prison issue pink shirt, saying: "There was a water tap that was running and mixing with the blood. The ground was pink like this shirt."
Evariste Maherane is a free man. After six years awaiting trial, he confessed and apologised at a Gacaca hearing. He sits at home near Nyarubuye with his wife, children and grandson.
He remembers killing a 10-year-old Tutsi boy who had escaped from the church.
Evariste held the wounded boy, dressed in his school issue khaki shorts and shirt, by the neck and battered him with a club. Then they dug a hole and pushed the child in, still alive.
Evariste had a 10-year-old son of his own at the time, and is haunted by the memory of the Tutsi child's arms and legs flailing in the smothering earth. "It was a time of hatred. Our heads were hot. We were animals", he says.
When we last met during the genocide, Flora had a serious head wound and I thought she had suffered brain damage. A decade later she is still suffering, but is lucid in her descriptions and has forgotten nothing.
She was at Nyarubuye church. The killers, including Gitera, hacked towards her with machetes, axes and hoes. I remember Gitera telling me: "It was as if we were competing over the killing."
Flora was knocked to the ground by bodies falling on top of her and the Interahamwe assumed she was dead. Later, one of the killers spotted her moving and smashed her head with a hammer.
But she survived among the rotting corpses for over a month before being found. "They helped me to sit up and I noticed the maggots falling off me," she recalls.
Flora lost 17 members of her family in the genocide and is furious that Gitera and others are being offered freedom.
"We have been patient, we have been strong - but a killer like that? I don't believe in the death penalty, but surely he should have been locked up for good," she says.
Another girl, who Panorama is not naming, was 20 at the time of massacre. She was hiding when Mayor Gacumbitsi drove past.
"He was a friend of my father", she says: "When I saw him I thought that no harm can come to me."
But Gacumbitsi was angry. He raped her and told the six policemen to do the same. "We are going to rape you to death," she remembers him saying.
She is only alive because a Hutu man, Gacumbitsi's deputy Matthew Fashingabo, and his wife gave her shelter and smuggled her out of the country.
Why had he acted with such bravery? "Because I know that we are all human beings," he says.
Marie was captured near Nyarubuye by Hutus who took her as a sex slave and raped her more than 100 times.
Marie contracted Aids from her rapists and afterwards discovered that she was pregnant. That baby died of Aids and Marie is now in the final stages of the disease.
She says: "I don't know why this happened to me. I was a good person. It wasn't my fault I was born a Tutsi."
Panorama: The Killers was broadcast on BBC One on Sunday, 4 April 2004 at 2215 BST