A suspect in the high-profile murder of Russian Army Colonel Yury Budanov has pleaded not guilty at the start of his trial.
Yusup Temirkhanov, an ethnic Chechen, is charged with killing Budanov, who was convicted of murdering a young Chechen woman.
In 2003, Budanov was sentenced to 10 years for the abduction and killing of 18-year-old Elza Kungayeva during Russia's bloody war in Russia's Chechen Republic in the North Caucasus. His early release on parole in 2009 sparked outrage among rights activists.
In June 2011, Budanov was shot dead in Moscow.
Investigators say Temirkhanov killed Budanov to avenge the death of his father at the hands of Russian forces during the Chechen campaign.
Temirkhanov denies any involvement in the crime.
Two other defendants will be tried separately.