It appears that mourners will begin gathering at Kitai-Gorod at 2:00 p.m. on Sunday, with the memorial march itself to begin an hour later, at 3:00 p.m.
Konstantin Merslikin, an official in Nemtsov's political party, says it is "99-percent sure" that Nemtsov's funeral will be held on March 3 at Moscow's Troyekurovsk Cemetery.
From our newsroom. We're trying to confirm the time, since that appears to be an hour earlier than previously reported.
The Moscow mayor's office granted permission to hold a march from Kitai Gorod to the Moscow City center on March 1.
Aleksei Mayorov, the head of the department for regional safety at the Moscow mayor's office, said the event would start at 2:00 p.m. local time and that permission was granted for up to 50,000 to take part.
More confirmation, via AFP, that Moscow authorities will permit a march in memory of Nemtsov.
An image of Tefft speaking to reporters during that visit to lay flowers at the crime scene:
LATEST: U.S. Ambassador to Russia John Tefft has laid flowers today at the scene of the Nemtsov killing, Russian and other media report.
Gleb Pavlovsky, a former Kremlin spin doctor, wrote on Facebook:
"A person who drives -- not just anywhere, but on Red Square to kill a former member of government, an opposition figure under the lights and video cameras of the Kremlin walls where hundreds are positioned -- is making a political demonstration. It is an address to the country and to the authorities that is no less powerful than an address from the president. Not to heed it and react to it will cost dear."
Our Russian Service is live-streaming clips (in Russian) of Nemtsov's colorful career, discussion of his legacy, and analysis of what his death means.
In a move that some are interpreting as a sign that any investigation might be seriously compromised, authorities appear to have washed away potential clues within hours of the killing. In this shocking video from our Russian Service, firemen use hoses to clean the crime scene as a crowd gathers.
