(MOSCOW) - They found the body of my friend Natalya Estemirova on Wednesday. She had been abducted by unidentified men that morning in Grozny, the capital of Chechnya, where she lived and worked as a human rights defender. She was seen being bundled into a sedan and was heard calling out, "I'm being kidnapped!" Calls to her cellphone went unanswered all day; she missed several important meetings, including one at the Ministry of Internal Affairs, and she failed to pick up her daughter as scheduled at 2:30 p.m.

I immediately feared the worst. The night before I had come back from a week of research in Chechnya with Natasha, as she was known, where we documented the extrajudicial executions, torture and -- ironically -- abductions that continue to go unpunished years after the Russian government declared the war there over. Anyone who challenges the authorities risks her life. We don't know who pulled the trigger on the gun that killed Natasha, but responsibility for the climate of impunity in Chechnya goes straight to Moscow.

Natasha was no rabble-rouser. She worked for the highly regarded Russian human rights organization Memorial. She received awards for her work from the European Parliament, the Swedish parliament and Human Rights Watch, where I am a researcher. In 2007, she received an international prize named for her friend Anna Politkovskaya, the journalist who was herself gunned down for her crusading reporting about the Chechen war.

Natasha was dedicated to exposing the gross misrule of Chechnya today. Among the most recent cases she publicized was that of Madina Yunusova, 20, who married a suspected Chechen militant last month. Yunusova's husband was killed in early July. Two days later, security forces came to her house, locked her mother, father and two sisters in the adjacent shed, and used gasoline to set the house on fire. The armed men unlocked the shed as they left, and Yunusova's family managed to put out the fire. The next day, the forces returned -- this time bringing Yunusova's body wrapped in a shroud, along with instructions to bury her "without noise."

As Natasha knew, "noise" is the only weapon against the grotesque abuses that civilians in Chechnya continue to suffer. She was a meticulous researcher, but she was also fierce in her determination not to submit to the fiction, so ardently purveyed by Russian Prime Minister Vladimir Putin and his circle, that Chechnya is quiet and that the problem there has been solved. It has not. House burnings have become a frequent form of collective punishment by local authorities, with at least two dozen incidents in the past year and a half. Suspected militants and collaborators, their relatives and any other perceived enemy of the regime can be tortured, abducted and assassinated.

Natasha had received many death threats and experienced many close calls over the years. Like Politkovskaya's death, her killing was both predictable and avoidable. Russian President Dmitry Medvedev has expressed his outrage at Natasha's death, but that is not enough. The Russian government must launch an immediate and thorough investigation into not only Natasha's death but the full range of human rights atrocities that have unfolded under the leadership of Chechen President Ramzan Kadyrov. That investigation should examine the role of official involvement -- including by Kadyrov.

Natasha is not the first Russian human rights defender murdered this year. In January, a friend of ours, Stanislav Markelov, a prominent human rights lawyer who helped many victims of abuse in Chechnya, was shot in central Moscow. Natasha came to town for his funeral. We sat at my kitchen table talking into the wee hours about Markelov and Politkovskaya and speculating about who would be next.

Now I know.

The killers of Markelov and Politkovskaya are still at large, and the Russian government has shown little political will to seriously investigate the murders of rights defenders. Natasha's death must be the moment this changes. That's where Western governments come in. We Russians have a saying, "The dogs bark, and the caravan moves on." Europe and the United States have found it convenient to let Chechnya slip off the agenda in their meetings with Russian policymakers. The dogs are barking.

The writer is deputy director of Human Rights Watch's Russia office.