The killing of Kremlin critic Politkovskaya drew attention to the risks faced by Russians who challenge the authorities and deepened Western concerns for the rule of law under President Vladimir Putin, who was then serving his second term.
Another jury's 2009 acquittal of three of the men who were found guilty of murder on Tuesday embarrassed Russian prosecutors and was later thrown out by the Supreme Court, which ordered a new trial.
The defendants included three Chechen brothers, one of whom was accused of shooting Politkovskaya in the lobby of her Moscow apartment building on Oct. 7, 2006, as well as their uncle and a former police officer.
Lawyers, rights activists and relatives of Politkovskaya say that justice will not be done until those who ordered her contract-style killing are identified and convicted.
A spokesman for federal investigators said the authorities are doing all they can to identify and track down the person behind the killing, Russian news agencies reported.