Security service investigators were trying to establish the motive for the murder of Galina Starovoitova, a highly respected liberal who was once a close aide to Boris Yeltsin.
Women are extremely rare in the upper reaches of Russian power, and her death marks the first occasion in which a senior female politician has fallen to an assassin's bullet. News that she was gunned down in the stairwell of her apartment in the middle of St Petersburg on Friday sent a wave of revulsion through the political establishment.The Kremlin dispatched the Interior Minister, Sergei Stepashin, to the city, and sent a telegram to parliament saying the investigation would be placed under Mr Yeltsin's "personal control".
It also issued a statement from the President describing her murder as "a peremptory challenge to the entire society" which "wounds every Russian who cherishes democracy". A shaken Yevgeny Primakov, the Prime Minister, appeared on television to appeal for "an immediate end to banditism".
Ms Starovoitova, a 52-year-old St Petersburg intellectual, was a rare example of a genuine democrat who never belonged to the Communist Party, or to the ranks of the apparatchiks who still tread the corridors of power. In the final years of Mikhail Gorbachev's rule she became a prominent voice, not least because her opposition to the Soviet system and fluent command of English appealed to the Western media.
Energetic and outspoken, she fought alongside Mr Yeltsin during his campaign for the Russian presidency and, after his election, became his adviser on ethnic affairs. Many also considered her the President's tutor in the principles of democracy.
She believed all ethnic demands for self-determination should be met, an opinion that in 1989 prompted the Armenians (campaigning for Nagorno- Karabakh's freedom from Azeri control) to elect her as a deputy to the USSR's first Congress of People's Deputies. But, as Mr Yeltsin drifted away from liberalism, she was soon sidelined.
In late 1992 she left the administration and eventually became a critic of the government, upbraiding it for its role in the Chechen war. But Ms Starovoitova remained in politics, becoming co-chair of the small Democratic Russia party and an active member of the Duma, the lower house. It was rumoured that she was considering a bid for the Presidency in 2000.
It is not known why two assassins - one of whom, according to Itar- Tass news agency, may have been a woman - attacked her with a machine gun and a pistol, killing her instantly and seriously injuring her male aide, Ruslan Linkov, a journalist. Rumours are circulating that she had been carrying a large sum of money, said to be party funds.
But her allies in Moscow were in little doubt that the motive was political and was evidence of Russia's poisonous and dangerous political environment. "There is no doubt that this was of a political character," said Alexander Shokhin, leader of "Our Home is Russia" party. "It is a great loss for all democratic forces in the country." Former Soviet president Gorbachev also said he believed it was a contract killing.
Why someone should order her death, however, is a mystery. But there will be no shortage of theories, including claims that it is linked with a political row over anti-Semitism. This erupted earlier this month when the Communist-dominated parliament refused to censure remarks by Albert Makashov, a retired general, who blamed Russia's woes on "Yids". There was an outcry in the liberal camp, led by Ms Starovoitova. Given the number of her enemies on the far left and right, suspicions are certain to take root that her murder was somehow connected.
However, contract killings of politicians and their aides has been common in Russia for some time, spawned by the unhealthy relationship between politics, business and money. Six MPs have been murdered since 1993. St Petersburg, where a killer can be hired for a few thousand dollars, has become a killing-ground.
Only last month an ally of the Duma speaker, Gennady Seleznyov, was killed by a bomb. An aide to another parliamentarian was shot dead in his apartment, and a local government official was killed the following day. Last year, St Petersburg's deputy governor - 36-year-old Mikhail Manevich, also from the liberal camp - was shot dead in his car. In Moscow earlier this year another prominent politician, General Lev Rokhlin, leader of a political group opposed to the Kremlin, was shot dead. Although the authorities blamed his wife, doubt over his murder has yet to be fully cleared up.
Most of these crimes did not hold attention for long. Slightly more exposure tends to be paid to murders of prominent women which, although exceptional, is not unprecedented. The assassination in June of opposition journalist Larisa Yudina attracted many column inches.
Most killings, however, are soon forgotten. The events of the past 48 hours in St Petersburg may just prove an exception - a crime so outrageous that it manages to stir the conscience of this blighted nation.