Although he feared for his life, Emmanuel Rudasingwa was determined to testify against his former mayor, the first person to be tried at the International War Crimes Tribunal for the 1994 genocide in Rwanda.
When he asked international investigators for protection, they advised him to call them if he was attacked.
The nearest telephone was more than 20 miles from his home.
His wife, Godelieve Mukasarasi, says he asked: "Should I call you when I'm dead?"
This week Rudasingwa was supposed to board a plane for the first time in his life and fly to to take the stand at the trial, which is being held in Arusha, Tanzania. But last month, a group of armed men raided his shop, asked the names of the 16 people inside, and opened fire - killing Rudasingwa, his daughter, brother, nephew, and seven others.
Though tribunal investigators don't know whether he was killed because of his role in their case, they privately admit that neither they - nor the Rwandan government - are doing enough to ensure the safety of genocide witnesses.
"We're rolling dice with their lives," says a tribunal official who spoke on the condition of anonymity.
The stakes are rising. The killings are part of a trend of rising violence since more than 1 million Rwandan refugees spilled home from Zaire and Tanzania late last year. The forced return ended more than two years of cross-border raids from refugee camps in Zaire, but now the fledgling government finds itself facing a growing internal threat.
The returnees are Hutus who fled Rwanda after the 1994 genocide of up to 1 million Tutsis and moderate Hutus and the government takeover by Tutsi rebels. Among those who returned are tens of thousands of Hutu militiamen and civilian killers who find sympathy and support in the countryside, where Hutus make up 85 percent of the population.
Parts of the northwest have become terrorist zones, with Hutu militants operating from the Gishwati forest. Dozens of civilians have been killed in the last few weeks in rebel attacks and cross-fire with the Rwandan Army.
Foreigners are also targets. Last week, UN human rights monitors suspended some of their operations after armed men beat up two expatriate workers, their interpreter and driver, burned their car, and threatened to kill them if they returned. On Saturday, unknown gunmen attacked the relief organization Doctors of the World, killing three Spanish workers and maiming one American volunteer.
But the biggest threat is to genocide survivors and witnesses. Too afraid to return to their homes, many cluster around commercial centers and military posts for protection. More than 200 were murdered last year, according to the UN, and with the recent start of genocide trials in both Arusha and the Rwandan courts, observers worry that killings will escalate.
Tribunal officials said last week that Rudasingwa's killing on Dec. 23 is the first murder of one of their witnesses.
The tribunal's budget last year was $37 million, but its witness-protection division is in Arusha, not Rwanda. And while witnesses who take the stand in Arusha are identified only by codes, back in their villages, where they face the most danger, the identities of "Witness K" and "Witness C" are well known.
The problem of witness protection could be even more acute as investigators build cases against the former government ministers, politicians, and top military officials accused of planning the genocide. Most of the witnesses privy to the inner workings of the old regime live in exile and are demanding relocation in exchange for their testimony, a tribunal official says.
That Rudasingwa was likely to appear in court was no secret. For the last year, investigators have rumbled over the rutted dirt roads in four-wheel drives, marked by black and white tribunal license plates. Usually, they parked in front of the houses of the people they interviewed as they built their case against Jean-Paul Akaseyu, the former mayor now on trial for allegedly leading massacres of Tutsis in Taba.
Rudasingwa's wife, a Hutu, said that, like her Tutsi husband, she too had heard Mr. Akaseyu order the killing of Tutsis during the genocide. But she refused to talk with tribunal investigators.
"It was too risky," she says. "Everybody could see who was being interviewed. I told myself, 'If that's the way it's going to be, I'm not going to do it.' "
Her husband decided to risk it. "There were no alternatives," she says. "Although he was afraid, he wanted to testify against the killers." The decision may have been his death sentence.
Rudasingwa's sister-in-law, Priscilla Musabire, who lives across the road from the shop, says she saw at least six men carrying rifles; some wore the khaki uniforms of the former Rwandan Hutu Army. Ms. Musabire's husband and son were among those killed.
"My husband had been trying to learn who killed his family [during the genocide]," Musabire says. "That's why they killed him. I think they were looking for him and his brother."