Supporters of a close ally of Slobodan Milosevic packed the smart Sava Centre in the city to hear the Patriarch of the Serbian Orthodox Church and the deputy of the ultra-nationalist politician Vojislav Seselj - who is standing trial on war crimes charges in The Hague - declare that the rest of the world had got it all wrong about the wartime atrocities. Tomislav Nikolic, Mr Seselj's deputy, told the meeting: "We are witnessing a synchronised media and political campaign to represent Serbs as people who commit genocide."
Last month it all looked so different. After a video showing members of the Scorpions paramilitary group executing six young Muslims was shown on Serbian television, the reluctance of Serbs to face the facts seemed to be dissolving. One Belgrade newspaper declared: "The truth has been smashed in our faces, painfully and mercilessly. The Serbian public is aghast, because it has finally seen that someone ... actually committed bestialities in uniform and with Serbian insignia."
Several members of the Scorpions were quickly arrested, and the Serbian President and Prime Minister denounced the crime. President Boris Tadic said he was ready to go to Srebrenica on the anniversary "to pay tribute".
And indeed, Mr Tadic is one of many dignitaries expected to bow their heads on Monday afternoon at the memorial centre in Potocari, in what was formerly a field of maize opposite the base of the Dutch UN peacekeepers. This is the place in which 25,000 refugees from the nearby town of Srebrenica were forced to huddle after the Dutch refused to admit them to their base, and from which the Bosnian Serb soldiers plucked them for execution like sticks of corn.
But back in Belgrade the new mood of contrition quickly curdled. A parliamentary motion condemning the Srebrenica killings as genocide was watered down to the point of being meaningless. Rumours that General Ratko Mladic, the military hard man who ordered the killings, and then Bosnian Serb president Radovan Karadzic, were on the verge of surrendering to The Hague proved once again to be moonshine.
Yet the massacres happened. Thanks to the Scorpions' video, to the testimony of a handful of witnesses - men who somehow escaped being shot by execution squads and crawled to safety - and to the confessions at The Hague of executioners, the events of those days are known in detail.
Mysteries remain, deliberately created by the perpetrators to bury their guilt. The victims of the slaughter were quickly dumped in mass graves. But as the world learned what had happened, the Serbs dug them up again and reburied them in many smaller sites. Many bodies were smashed into pieces by the heavy diggers, and the fragments churned in new graves with the remains of other victims.
Slowly those mysteries are being untangled, thanks to a project that combines compassion and high science. Operating out of a number of cramped and unpretentious quarters around Bosnia, the International Commission on Missing Persons (ICMP) has been labouring for four years to match the DNA of blood samples of surviving relatives with that of bone samples of victims, and thereby put names and faces to the sad aggregations of bones, clothing and personal possessions.
There are the body bags, many thousands of them, sacks of remains gathered from the graves and stored for analysis at a funeral home in the town of Lukavac, near Tuzla. Cheryl Katzmaryk, a forensic anthropologist, and her team puzzle and worry the bones into complete bodies, using every trick in the detective's book to shed light. "This is a very young person," says Ms Katzmaryk, poring over a small heap of bones reeking of ammonia, "in his mid-teenage years. When we are born we have 806 bones; when we mature we have 206 - many of his bones have not fused yet." As well as bones there is a pile of fine rubble. "This is pulped for anything it can tell us - teeth, for example are incredibly valuable for DNA analysis. We want to make sure we recover everything."
At another ICMP centre in a decaying 1970s megastructure in Tuzla, survivors come to give the tiny blood samples required for DNA analysis. They also offer information about their husband or father or son in the hope that some fragment may lead the ICMP people to locate his remains: the clothes he was wearing, the photographs in his wallet, spectacles, worry beads. And slowly the living and the dead are reunited, and the bereaved are allowed to mourn.
At the memorial centre in Potocari where President Tadic will pay his respects tomorrow, already 1,327 graves have been filled and marked, each with an identical wooden marker painted green. Today many graves stand open; during the ceremony tomorrow 583 will receive their tenants, individuals identified and named by ICMP.