Not much is known about the underworld kingpin known as Grandpa Hassan, except that somebody really wanted him dead.
Two years ago, assailants rented an apartment across four lanes of traffic from his son’s house and then lay in wait for three months for Grandpa Hassan, whose legal name was Aslan Usoyan. When he finally appeared, the gunman wounded but did not kill, hitting his target in the abdomen.
On Wednesday, a better-placed shot over a busy street in downtown Moscow found its mark. Mr. Usoyan, who also survived a 1998 attack, was 75.
A gunman fired from the House of Actors, a Soviet-era apartment building, apparently while hiding in the attic, Sergei Kanev, a crime reporter for Novaya Gazeta, said of the killing, which was one of the highest-profile contract murders in the Russian capital in recent years.
Mr. Usoyan, an ethnic Kurd from Georgia, was walking out of an Azerbaijani restaurant where he often held meetings, Mr. Kanev said. He was still breathing when he arrived at a hospital but died soon afterward, Interfax reported, citing doctors. There were no immediate arrests.
Since the 2010 attack, Mr. Kanev said, Mr. Usoyan, who bore a passing resemblance to Leonid Brezhnev, “knew he would die, no matter how he tried to protect himself.” He added, “There was no other ending.”
The affair seemed a throwback to the brazen, bloody gangland wars in Russia in the early post-Soviet period, an era of ill-fitting suits, car bombs and drive-by shootings when Mr. Usoyan gained notoriety.
Experts on Russian organized crime said his role was that of a banker — the underworld term is obshank — holding a common pot of funds for many different gangs. He also mediated disputes.
“I wouldn’t say there was anybody more powerful than Hassan” in Russian organized crime, Mark Galeotti, an authority on Russian criminality at New York University, said in a telephone interview.
Why he became such a target is still something of a mystery, especially given that violent street crime dropped sharply during the tenure of President Vladimir V. Putin, and other notorious gang leaders, men with nicknames like Little Japanese, Mr. Lisp or Tomato, walked free.
“The mob wars of the 1990s had run their course” by the time Mr. Putin came to power in 2000, Dr. Galeotti said. “There were no established pecking orders or turf then, but what came out of those mob wars was precisely a hierarchy and a sense of division of assets.”
And Mr. Putin, he said, let it be known that “overt gangsterism in the streets that would undermine the authority of the state” would be punished severely, even while the hierarchy was left intact.
Mr. Usoyan’s murder may change that, Dr. Galeotti said, particularly as lucrative construction contracts for the 2014 Winter Olympics and heroin-trafficking routes from Afghanistan are introducing new objects of competition for organized crime groups.
Prosecutors theorize that Mr. Usoyan may have been embroiled in a dispute with his reputed former partner, who is now serving a prison sentence in Spain for money laundering.
Whatever the case, history shows that prosecutors can expect little help from the Russian government in solving the mystery of who killed Mr. Usoyan. According to an American diplomatic cable published by WikiLeaks, American diplomats meeting in 2009 and 2010 with Spanish prosecutors were told that the government of Russia, referred to as the G.O.R., appeared to be cooperating with, rather than prosecuting, organized crime figures.
In return, the prosecutor said, the gangsters “do whatever the G.O.R. cannot acceptably do as a government,” like carrying out contract killings of Russian citizens in foreign countries.
On Wednesday, while vowing to investigate, Russian law enforcement officials offered little in the way of sympathy for Mr. Usoyan.
“The fewer bandits, the better for the people,” Aleksandr Mikhailov, a former deputy commander of Russia’s antinarcotics police force, told Interfax.
This story, "," originally appeared in The New York Times.