Moscow (CNN) -- Russian investigators were hunting Thursday for the assassin of a reputed Russian mafia kingpin who was fatally shot by a sniper outside a restaurant in central Moscow.
Aslan Usoyan, also known as Granddad Khassan, was the target Wednesday afternoon of what appears to be a contract killing amid a gangland turf war, state media said.
A restaurant worker injured in the shooting was in a critical condition Thursday, state-run Itar-Tass news agency reported, after being hit by two bullets.
She suffered damage to her spine and lungs, and is on a ventilator, the news agency reported.
A doctor told the state-run Russia 24 channel that the 30-year-old woman might not walk again.
Russia's Investigative Committee, which is probing the attack, said the killer had used a VAL assault rifle fitted with a silencer.
The weapon is standard issue for military special task force units, according to Itar-Tass.
Usoyan, who was in his 70s, suffered a single bullet wound to the neck, the committee said.
Two bodyguards who were with Usoyan administered first aid in the restaurant on Povarskaya Street, but their boss later died in the hospital.
One bodyguard returned fire in the apparent direction of the shot but had to retreat into the building after coming under further fire from the assassin, the committee said.
The assassin fled the scene without being caught.
Investigators later found the spot where the killer had waited to take aim, the committee said -- a stairway between the fifth and sixth floors of a nearby building. Six shells were found there, along with a camp chair and piece of fabric.
Involved in the criminal underworld since the 1960s, Usoyan had survived at least two previous attempts on his life, one in 1998 and the other in 2010, state-run RIA Novosti reported.
He was involved in gambling, drug trafficking, illegal arms sales and extraction of mineral resources, it said, and controlled organized crime groups in Moscow and across the country.
CNN's Alla Eshchenko and Phil Black in Moscow, and Laura Smith-Spark in London contributed to this report.