48, was found dead with a gunshot wound to the head in an elevator in
her apartment building at 8/12 Lesnaya Ulitsa near Belorussky Station
in central Moscow.
The killing of the Novaya Gazeta reporter outraged journalists and political leaders in Russia and was met with shock and sorrow in Western countries. As of Sunday evening, the Kremlin had made no comment.
On the day of her murder, Politkovskaya had planned to file a lengthy story on torture practices believed to be used by Chechen authorities, Novaya Gazeta editor Dmitry Muratov said.
Those accused in the story of practicing torture belong to security detachments loyal to Chechnya's pro-Moscow Prime Minister Ramzan Kadyrov, Muratov said. The detachments are known as kadyrovtsy.
Now the story may never be published. What's more, Muratov said, two photographs of the suspected torturers have disappeared.
Politkovskaya's body was discovered by a neighbor between 4:30 p.m. and 5 p.m.
Investigators found a pistol and four 9-millimeter bullet casings at the scene, First Deputy City Prosecutor Vyacheslav Rosinsky said in televised comments.
Politkovskaya was carrying grocery bags, apparently having just returned from a Ramstore supermarket, when she was gunned down.
Footage from a security camera in the apartment building foyer showed the presumed killer, a tall young man wearing dark clothing and a black baseball cap.
Prosecutor General Yury Chaika will personally oversee the investigation, his office announced Sunday.
Chaika's office said investigators were considering Politkovskaya's professional work as the primary motive for her murder.
Most of Politkovskaya's colleagues, friends and acquaintances interviewed believe the killing was ordered by those seeking revenge for her reporting on corruption or Chechnya.
"There can be no other reason," said Alexei Venediktov, editor of the Ekho Moskvy radio station and a friend of the journalist. "She had no other life apart from her profession."
Vitaly Yaroshevsky, a deputy editor at Novaya Gazeta, had no doubts why Politkovskaya had been killed. "There is no question this is politically motivated. I can't rule out that this was a murder ordered from above."
The editors are apparently not counting on authorities to bring the reporter's killer to justice: Muratov pledged that the paper would conduct its own investigation.
Billionaire State Duma deputy Alexander Lebedev, who bought 90 percent of Novaya Gazeta in June, has posted a reward of 25 million rubles, just under $1 million, for information leading to those responsible for Politkovskaya's death, Ekho Moskvy reported.
Yaroshevsky said investigators came to the newspaper offices at around 7 p.m Saturday. They searched Politkovskaya's office and confiscated books and the hard disk from her computer, he said. On Sunday, investigators appeared to have removed the base unit of her computer, Yaroshevsky said.
"We fully understand that the investigators need all this information, and we are cooperating," Yaroshevsky said.
On Sunday, Kadyrov, whom had repeatedly been criticized by Politkovskaya in her articles, and Chechen President Alu Alkhanov voiced shock at her killing.
Kadyrov said he had, at times, questioned Politkovskaya's objectivity but deplored her killing. He also cautioned against any speculation that a "Chechen trail" would lead to the guilty parties, Ekho Moskvy reported Sunday.
Venediktov speculated that the journalist may have been targeted by ultranationalists. Her name had been included on several lists of so-called enemies of the Russian people on ultranationalist web site.
And Venediktov said her killing might have been a demented birthday gift for President Vladimir Putin, who turned 54 on the day of Politkovskaya's death.
On Sunday, pro-Kremlin electronic media were awash in speculation that the killing had been ordered by anti-government forces seeking to replicate the rallies sparked by the killing of Ukrainian journalist Heorhiy Gongadze.
Gongadze had written several articles critical of Ukrainian President Leonid Kuchma. He disappeared in September 2000. His decapitated body was discovered two months later outside Kiev.
The killing sparked demonstrations in Kiev from December 2000 through February 2001, helping to foment the opposition to Kuchma that led to the Orange Revolution of late 2004.
Politkovskaya's killing, explained Maxim Shevchenko, a commentator for Channel One state television, was "an attempt to provoke an Orange Revolution here," RIA-Novosti reported.
Former Soviet President Mikhail Gorbachev, a co-owner of Novaya Gazeta, said the killing might have been intended to cast a pall over Putin's Kremlin. Former Prime Minister Boris Nemtsov dismissed that suggestion.
"What pall? There have been so many palls cast on the current authorities and to no avail," Nemtsov said.
On Sunday, more than 500 demonstrators descended on Pushkin Square to protest Politkovskaya's killing. "The Kremlin has killed freedom of speech," one poster declared.
Four activists from the pro-Kremlin group Young Russia tried to disrupt the rally, which had been planned as a show of support for Georgians and turned into a protest against Politkovskaya's death.
The four, all men, unfurled a sign at the rally reading: "Politkovskaya is a Russian Gongadze. Orange Creatures, You Will Pay for Her Death." The men were quickly overwhelmed by demonstrators; their sign was torn to pieces.
The slaying is the highest-profile murder of a journalist in Russia since Paul Klebnikov was shot dead after leaving work in July 2004. Klebnikov, the American editor of the Russian edition of Forbes magazine, had spent years reporting on Russia's rich and powerful.
If history is any indicator, Politkovskaya's killer is unlikely to be brought to justice.
No one has ever been convicted of the high-profile slayings of Klebnikov or journalists Dmitry Kholodov, Vladislav Listyev and Larisa Yudina. The Russians were all killed in the 1990s.
Over the past 15 years, Russia has become the third-deadliest country in the world for journalists, after Iraq and Algeria, according to the Committee to Protect Journalists. Since 1992, the group said, 42 journalists have been killed in Russia; the majority of the murders have never been solved.
Politkovskaya is survived by her son, Ilya, and daughter, Vera. Both are in their early 20s, Yaroshevsky said.
Politkovskaya's ex-husband, Alexander Politkovsky, one of the hosts of the perestroika-era cult television program "Vzglyad," said Saturday that his ex-wife had been a "principled, honest journalist."
"She was a person from another time," he said.
The funeral is set to be held Tuesday at 2:30 p.m., at the Troyekurovsky Cemetery.
Staff Writers Nabi Abdullaev, Catherine Belton and Simon Saradzhyan contributed to this story.