The shooting of Ms. Estemirova, 51, in July 2009 has so far produced only an incomplete investigation, and no charges have been filed against anyone involved. Her case has instead turned into an example of what often happens in Russia when high-ranking officials fall under scrutiny. Retaliation follows, and the accuser becomes the accused.

Mr. Orlov, who first raised his voice against official wrongdoing as an anti-Soviet pamphleteer in the 1980s, has found himself under an unrelenting legal siege from the Chechen leader, Ramzan A. Kadyrov.

Mr. Kadyrov’s attempt to silence Mr. Orlov reflects an increasingly common tactic in Russia. The authorities do not summarily imprison their critics as dissidents, as in Communist times. They instead often invoke an array of civil and criminal charges, including defamation, to exact financial penalties or prison sentences. They haul their opponents before judges who are wary of handing down decisions against those in power.

Mr. Kadyrov, who denies any connection to Ms. Estemirova’s killing, rules unchallenged in Chechnya. Still, he has portrayed Memorial as a treacherous and violent organization. In seeking charges against Mr. Orlov in Moscow, 1,000 miles from Chechnya, he effectively quashed the idea that the Russian capital offers sanctuary for those pursuing human rights issues in remote regions. No one from the Kremlin has come to Mr. Orlov’s defense.

Mr. Kadyrov’s lawyer, who under the law can work with the prosecution during the proceedings, has even used the trial to promote his own black-is-white theory of Ms. Estemirova’s death. “Maybe Memorial itself ordered the killing” to discredit Mr. Kadyrov, said the lawyer, Andrei A. Krasnenkov.