Hundreds of people paid their respects Tuesday to the memory of opposition leader Boris Nemtsov, who was assassinated in February just meters from the Kremlin.
Supporters squeezed onto the narrow pedestrian walkway of a bridge where Nemtsov died to place flowers to mark the 40-day memorial, an Orthodox Christian tradition.
Police set up barricades as the number of well-wishers spilled onto the bridge. A "minute of non-silence" was marked at 11 a.m., Moscow time, with passing cars honking their horns in support and a show of respect.
Opposition leaders attending the memorial repeated calls for a permanent memorial plaque or re-naming the bridge "Nemtsov Bridge" - after nationalist vandals in March damaged a temporary memorial.
They also expressed skepticism and criticism about the government investigation into the assassination.
Opposition leader Vladimir Ryzhkov said he was not satisfied with the ongoing investigation. Ryzhkov said that there are 18 webcams in the area where Nemtsov was shot dead. It is under total control of the secret service, he added.
“After 40 days we do not know the names of those who committed [the crime], and most important, we do not know the names of those who ordered it. I am personally convinced that President Vladimir Putin knows the whole picture of the crime,” said Ryzhkov.
"He knows those who were shooting, and those who were driving, those who were eavesdropping, those who were leading the way and most important, those who gave the order and paid money for this murder,” said Ryzhkov.
Before his death, Nemtsov was working on a report critical of Russian involvement in the armed conflict in eastern Ukraine, his associates have said.
Nemtsov's close friend Ilya Yashin, who has worked to finish the report, said he hoped to present the report in Moscow by the end of April.
“You know, I have no idea whether our report will change something or not, but I understand that one should do what he has to and then come what may. I understand that the first step towards changes in our country lies in telling people the truth,” he said.
"That Russian soldiers die in Donbass that Putin started a bloody massacre, that this is a war that needs to be stopped. We are trying to tell the largest number of our compatriots about it. What conclusions the citizens will draw is up to them,” said Yashin.
Several Chechen men were arrested for the killing but the opposition and independent analysts say they are scapegoats and that those who ordered the murder likely will never be revealed.
The five suspects, all from the predominantly Muslim republic, are still being detained. Supporters of Nemtsov, however, believe that by casting blame on Islamic extremists, investigators are attempting to shift responsibility away from the government and onto a minority with a controversial reputation.
Chechnya suffered two intense wars over the past two decades between Russian forces and separatist rebels increasingly under the sway of fundamentalist Islam. That has reinforced the stereotype among many Russians of Chechens as violent extremists.
The key suspect, Zaur Dadaev, told a court last week that he had been beaten and pressured to confess. Dadaev had been an officer in the Chechen police force, supervised ultimately by Chechen leader Ramzan Kadyrov.
Yashin told The Associated Press that investigators may have found the man who pulled the trigger but the mastermind is still on the loose.
“Those people directly responsible for organizing the murder are now in Chechnya under the protection of Kadyrov and his militia,” Yashin said. “If the people who ordered the killing are not sent to prison, they will believe in their own impunity and their right to solve problems in any way they please.”
VOA Moscow Correspondent Daniel Schearf and cameraman Mike Eckels contributed to this report. Some material came from The Associated Press and Reuters.