Police said an unidentified gunman fired seven shots from a sniper rifle at Aslan Usoyan near a restaurant in central Moscow - the third assassination attempt on him since the late 1990s.
Usoyan, also known as Grandpa Khasan, was a 75-year-old ethnic Kurd born in the former Soviet republic of Georgia. Police say for the past two decades he headed one of the region's most powerful criminal groups, which trafficked in drugs and weapons and controlled underground casinos as well as many legal businesses, including those in the construction industry.
Police said Usoyan was hit in the jaw, hospitalized in a coma and then died. Police said the gunman, who used a state-of-the-art automatic rifle issued to Russian special forces, also injured a passerby, who was hospitalized.
Usoyan came from a caste of professional criminals who sport elaborate tattoos, follow unwritten prison laws codified in Stalinist-era Gulags and have been romanticized in countless popular songs.
He was first convicted in 1956 in Georgia and soon became a professional criminal. Like other members of his caste, he was strictly forbidden from befriending men in uniform, avoided luxurious lifestyles, never got married and considered prison his only true home.
Having survived the totalitarian system that spawned them, Russian criminals enjoyed a heyday in the decade after the 1991 fall of the Soviet Union. Usoyan opened a chain of casinos in Moscow and became the keeper of an emergency fund for jailed Russian criminals - a position that gave him immense authority in the criminal underworld of the vast former Soviet Union.
By the early 2000s, he had consolidated control over criminal groups in southern Russia that united natives of Georgia, Armenia and Azerbaijan as well as ethnic Russians. He feuded with mobsters who became more like Italian mafia and often disregarded Soviet-era prison norms.
Since 2006, Usoyan had been at war with a criminal group headed by another Georgian, Tariel Oniani, according to organized crime experts.
Russian media said the battle between the two clans had intensified in recent years as they vied for control over construction projects in southern Russia, including the huge sports facilities being built for the 2014 Winter Olympics in Sochi.