Government investigators blamed the insurgents, saying they had intended to embarrass the Chechen regional government led by Ramzan A. Kadyrov, himself a former insurgent whose family had flipped to the government side. The Investigative Committee, a Russian law enforcement agency, did not respond on Tuesday to a request for comment on the case.
The European Court of Human Rights, based in Strasbourg, France, is a venue of last resort for rights cases in Russia. The Russian government is treaty-bound to observe its rulings, part of an early post-Soviet effort to integrate Russia into the wider European human rights architecture.
Estemirova v. Russia was one of the higher-profile cases to come before the court in years, and the ruling Tuesday represented a partial vindication for Ms. Estemirova’s sister, Svetlana Estemirova, who filed the appeal in 2011.
Svetlana Estemirova had asked the court to find that Russian security services had violated her sister’s right to life under an article of the European Convention of Human Rights.
The court has repeatedly ruled against the Russian government, including in multiple cases of forced disappearances in Chechnya.
In the ultimately successful Russian campaign to pacify an Islamist uprising in Chechnya during the second of the region’s two post-Soviet wars, which began in 1999, targeting family members of fighters became a trademark Russian counterinsurgency tactic. American commanders in Iraq and Afghanistan, by contrast, have said that they did not deliberately target family members.
Rights groups estimate that about 5,000 people disappeared during the Russian operations and have documented the practice of punitive house burning and the abduction of family members to force the surrender of insurgent relatives.