Bosnian Serb general Ratko Mladic made a throat-slitting gesture to a woman who lost her son, husband and brothers in the Srebenica massacre at the start of his trial on Wednesday for some of the worst atrocities in Europe since World War Two.
Mladic, now 70, flashed a defiant thumbs-up as he entered the courtroom - the last of the main protagonists in the Balkan wars of the 1990s to go on trial at the International Criminal Tribunal for the former Yugoslavia in The Hague.
A hero to Serb nationalists, the "Butcher of the Balkans" to his Muslim and Croat victims, the pugnacious general eluded justice for 16 years until his capture in a cousin's farmhouse in Serbia last May.
The list of 11 charges stemming from his actions as the Serb military commander in the Bosnian war of 1992-95 ranges from genocide to murder, acts of terror and crimes against humanity.
He is accused of orchestrating not only the week-long massacre of 8,000 unarmed Muslim men and boys in Srebrenica but also the 43-month siege of the Bosnian capital Sarajevo, in which more than 10,000 people were killed by snipers, machine guns and heavy artillery.
Mladic, who refused to enter a plea, cuts a much frailer figure now than his bullish, strutting wartime persona - his defence lawyer said he had suffered three strokes and a heart attack. But he appears to have lost none of his defiance.
In the public gallery, Munira Subasic, whose 18-year-old son, husband and brothers were killed in Srebrenica, stared at him from behind a glass barrier, crossing her wrists to imitate handcuffs.
Mladic stared back and ran a hand across his throat. Presiding judge Alphons Orie promptly called a brief recess and ordered an end to "inappropriate interactions."
"I thought I would see at least some remorse in his eyes when I came here," Subasic said. "But instead I saw his bloodthirstiness. I don't know how he can live with what he did, with killing so many people."
The proceedings were broadcast live on big screens in Sarajevo, where thousands were killed by snipers or artillery while queuing for water or bread, or crossing the street.
Hasna Hadzic, a pensioner who spent the war in Sarajevo, stopped off on her way from the market, visibly shaken.
"I feel like crying when I think of what he has done to us: killed 8,000 in Srebrenica alone, killed people in Foca, Visegrad, our children in Sarajevo," she said, wiping tears from her face.
"They shouldn't have put him on trial. They should have liquidated him immediately."
"They let him walk free for 16 years," said pensioner Asim Dzemat. "The whole world let him kill us for years, and now they address him as 'Mr' Mladic, 'General' Mladic! What 'Mr'? He's a killer! It's so shameful."
But in Pale, the mountain stronghold from which Serb forces orchestrated the siege and bombardment of the capital 16 km away, applause broke out in cafes every time Mladic appeared on the television screens.
"Crimes were committed by all sides," said Serb student Mladen Mancic. "This is just an honourable man who defended the Serb people. If it wasn't for him we wouldn't be here today."
Mladic was in charge of the Bosnian Serb army when, over several days in July 1995, Serb fighters attacked the Srebrenica enclave in eastern Bosnia, theoretically under the protection of Dutch U.N. peacekeepers.
Video footage shot at the time showed Mladic mingling with Muslim prisoners. Shortly afterwards, the men and boys were separated from the women, stripped of identification, and shot.
Prosecutor Dermot Groome, beginning a two-day opening statement, said Mladic and other Bosnian Serbs had been implementing a grand plan to eliminate non-Serbs from large areas of Serbia, Bosnia and Croatia.
"The prosecution will present evidence that will show beyond a reasonable doubt the hand of Mr Mladic in each of these crimes," he said.
Prosecutors screened footage of bodies piled up on the streets of Sarajevo and people running in terror from the Serb onslaught.
"There can be no doubt that Mladic controlled the shelling of Sarajevo," Groome said.
"Mladic participated in a campaign of sniping and shelling against the besieged city of Sarajevo in order to spread terror among its civilian population."
Mladic is also held responsible for the imprisonment of non-Serbs in a system of camps, including Omarska, Prijedor and Keraterm, where they were raped, abused and murdered.
The horrors of the Sarajevo siege and the Srebrenica massacre eventually galvanised world opinion in support of the campaign of Western air strikes on Bosnian Serb targets that brought the conflict to an end.
Mladic was indicted in 1995 along with Radovan Karadzic, the Bosnian Serbs' political leader, who is also on trial in The Hague. Yet both remained free in Serbia for more than a decade before being tracked down.
Mladic, who was arrested last May, has dismissed the charges as "monstrous" and says he is too ill to endure a trial that could last two years or more. By the end of the hearing he looked tired, and was given medication.
Some victims fear that time and failing health could help him avoid judgment like his mentor Slobodan Milosevic, the architect of the Balkan wars, who died in detention in 2006 - a few months before a verdict in his trial for genocide and other war crimes in Croatia, Bosnia and Kosovo.
Defence lawyer Branko Lukic said that after three strokes and a heart attack, Mladic "will never be ok", but that his health had been improving thanks to treatment in detention.
It is estimated that the prosecution case alone will last 200 hours, with testimony from 411 witnesses, and defence lawyers say they have not had have enough time to review the huge case file.
The judges said on Wednesday that prosecutors had made "very significant errors" in disclosure of evidence, and that they would consider giving the defence more time.