A Russian man accused of stabbing an air traffic controller to death in 2004 after the loss of his family in an air crash has gone on trial in Switzerland.
Vitaly Kaloyev's wife and two children died in the plane crash
Vitaly Kaloyev, 48, lost his wife and two children in a mid-air plane collision that killed 71 people in southern Germany in July 2002.
It occurred in Swiss-run airspace while Danish-born Peter Nielsen was alone on duty at Zurich air traffic control.
Prosecutors want a 12-year sentence, and a verdict is due on Wednesday.
There have been rallies of support for Mr Kaloyev in Moscow and North Ossetia, his home region.
The BBC's Russian affairs analyst, Steven Eke, reports that the accident caused outrage in Russia after the Swiss authorities covered up long-running staff and technical problems in air traffic control by wrongly blaming the Russian pilots for the accident.
Most of the dead were children going on holiday to Spain.
Mr Kaloyev is charged with premeditated killing - a charge which sits between murder and manslaughter under Swiss law.
He was working as an architect in Spain at the time of the crash, and his wife and children had been on their way to visit him.
He earlier made a partial confession but insists the attack on Mr Nielsen, who died in front of his own three children, was not already premeditated.
"I went to Nielsen as a father who loves his children so he could see the photos of my dead children and next to them his kids, who were alive," Mr Kaloyev said in court.
"Everyone can make mistakes, but these are my children," he added.
According to the prosecution, he killed Mr Nielsen in revenge for his family members' death by stabbing him in the backyard of his Zurich home in February 2004.
After Mr Nielsen's death, a German investigation concluded he had been responsible for the crash.
The President of North Ossetia, Taymuraz Mamsurov, who is attending the trial in a private capacity, said he hoped a humane and just decision would be reached.
The crash involved a Russian passenger plane from Moscow to Barcelona and a DHL cargo plane headed for Brussels.
Mr Nielsen, who had not been told that the collision-avoidance system was not fully working, warned the pilots only 43 seconds before they collided.
The investigation into the accident, by Swiss, German, Russian and American specialists, revealed numerous shortcomings in the work of SkyGuide, the Swiss air-traffic control service.
However, to Moscow's fury, SkyGuide blamed the Russian crew.
Most seriously, they repeatedly accused them of failing to carry out instructions when ordered. That turned out to be untrue.
In Russia, Mr Kaloyev's actions are widely seen as a crime of passion, our analyst notes, and many Russians see the initial Swiss response as a demonstration of anti-Russian prejudice.
SkyGuide has since accepted full responsibility and asked relatives of the victims for forgiveness.