By Matt Prodger
BBC Belgrade correspondent
Serbia has begun a trial of five former members of a police unit who allegedly filmed themselves murdering civilians during the Bosnian war.
Video footage shows victims with their hands tied behind their backs
Prosecutors say the video provides the first visual evidence of Serb forces carrying out the Srebrenica massacre of 1995, in which nearly 8,000 Muslim men and boys died.
It was the worst atrocity committed in Europe since World War II.
The trophy video - which lasts about 20 minutes - shows several members of the "Scorpions" police unit with six Muslim prisoners dressed in civilian clothes.
Five of the captives have since been identified as Safet Fejzovic, Sadik Saltic, Smail Ibrahimovic, Fadil Salkic and the youngest, aged 16, Azimir Alispahic.
They were all Muslims from Srebrenica who were captured when the town fell to Bosnian Serb forces in 1995.
The prisoners - dirty, bruised and with their hands tied behind their backs - are ordered from the back of a lorry in which they had been transported from the Srebrenica area.
They are marched to a clearing in woodland near Sarajevo, where, one by one, four of them are shot in the back. Two more are forced to move the bodies of their fellow victims, before they too are shot.
At one point during the executions the cameraman, apparently drunk, is heard complaining that the battery on the camera is running down.
The video shows six men being led away from a lorry and shot
The film lay hidden for 10 years before a former member of the Scorpions contacted a Serbian human rights activist, Natasa Kandic, with information as to its whereabouts.
The video was then secretly passed on to war crimes prosecutors both in Serbia and at The Hague tribunal.
After the gunmen in the video had been identified and tracked down, it was broadcast on TV news bulletins across the former Yugoslavia and beyond.
It has been used as evidence in the trial of the former Serbian and Yugoslav President Slobodan Milosevic.
Hague prosecutors say the killers ultimately took their orders from Belgrade.
"I was sure that ordinary people here would react as human beings when the tape was broadcast, that the video tape would finally convince Serbs of what happened in Srebrenica," says Natasa Kandic. "And many people did contact me to tell me how shocked they were.''
Five months on from that broadcast, many Serbs are still appalled by what they saw.
"It's disgusting and shameful for our country and I'm absolutely in favour of the perpetrators being punished,'' one student at Belgrade University told me.
But his colleague saw it differently.
"That was a war and those men that you see killed were potential enemies,'' he said.
"They had to kill them. Unfortunately they had to kill them.''
During the Balkan wars of the 1990s, TV viewers here were fed a diet of propaganda which portrayed Serbs as the greatest victims of the conflict.
Opinion polls suggest that most still believe the Srebrenica massacre to have been exaggerated by Western media.
The two men accused by The Hague of genocide at Srebrenica - former Bosnian Serb leader Radovan Karadzic and his military counterpart Ratko Mladic - are considered heroes by many. They remain at large.
Srebrenica - a UN-protected enclave - fell to the Serbs in July 1995
Tuesday's trial represents the first time that a Serbian court has heard a case directly related to Srebrenica.
The same court earlier this month completed the first war crimes trial in Serbia, with the conviction of 14 people for killing 200 prisoners during the 1991 siege of Vukovar, in Croatia.
"It's very important that we are now judging the people who committed atrocious crimes in our names,'' says Serbia's chief war crimes prosecutor Vladimir Vukcevic.
The former Scorpions - Slobodan Medic, Pero Petrasevic, Aleksandar Medic, Aleksandar Vukov and Branislav Medic - were separated from the court and public gallery by 80 tonnes of bullet-proof glass.
Relatives of the victims travelled to Belgrade from Bosnia to attend the trial.