One by one, thousands of mourners and dignitaries filed past the white-lined coffin of slain Kremlin critic Boris Nemtsov on Tuesday, many offering flowers as they paid their last respects to one of the most prominent figures of Russia's beleaguered opposition.
So many arrived that when the viewing ended after its scheduled four hours, people in a line hundreds of yards long still waited outside the Sakharov Center, named after the Soviet-era dissident and Nobel Peace Prize laureate Andrei Sakharov.
Nemtsov was shot to death late Friday while walking on a bridge near the Kremlin with his girlfriend, Anna Duritskaya. No suspects have been arrested.
The killing has deeply shaken Russia's small and marginalized opposition movement. Many opposition supporters suspect the killing was ordered by the Kremlin in retaliation for Nemtsov's ardent criticism of President Vladimir Putin. Authorities have suggested several possible alternatives, including that Nemtsov was killed in an attempt to tarnish Putin's image.
"The shots were fired not only at Nemtsov but at all of us, at democracy in Russia," Gennady Gudkov, a prominent Kremlin opponent, said in a speech delivered next to the coffin. "We never thought this could happen, but it did. Rest in peace, my friend. Your work will be continued."
Nemtsov, a former deputy prime minister, is the most prominent opposition figure to have been murdered in Russia during Putin's 15-year rule.
The only current Kremlin figure of any standing to attend was Deputy Prime Minister Arkady Dvorkovich, who joined mourners filing into the hall where Nemtsov's open casket was on display. Dvorkovich, from the Kremlin's increasingly sidelined liberal camp, carried red flowers.
Several European dignitaries said they were unable to attend the ceremony because Russian officials would not let them into the country.
For the most part, mourners were die-hard Kremlin opponents who feel deep alarm over Nemtsov's killing. But they represent only a minority of the Russian population; polls show most Russians support Putin, despite a plummeting ruble and international sanctions over the Ukraine crisis.
Russian investigators say they are working to track down Nemtsov's killers. The Investigative Committee handling the case said it has obtained closed-circuit television footage from the scene and has scheduled ballistic and medical tests.
Duritskaya has returned to her native Ukraine, the committee said in a statement. It said she has given evidence and promised to continue to cooperate with investigators.