A 21-year-old Russian soldier was sentenced to life in prison on Monday for shooting a civilian to death, in Ukraine's first war crimes trial. The court in Kyiv on Monday considered his guilt proven after the soldier's confession that he shot an unarmed 62-year-old civilian on February 28, four days after Russia launched its invasion of Ukraine. The trial marks the first war crimes case to be heard in court since the start of the Russian invasion, following worldwide horror at Russian atrocities in Ukraine. The defendant, Vadim Sh., now has 30 days to appeal the verdict, which is not yet final. The shooting occurred in the village of Chupakhivka in Ukraine's north-eastern Sumy region. The victim, Oleksandr Shelipov, was out with his bicycle when the defendant fired at him with a Kalashnikov assault rifle, according to the evidence gathered in court. Shelipov's widow later found her husband dead on the road, shot in the head. 'He was everything for me. He was my protector,' she told the court. Vadim Sh., a tank soldier from Irkutsk in Siberia, said he had acted on orders from his superiors. He apologized during the trial. 'I regret it. I regret it very much. I did not refuse and I am ready to accept any measures imposed,' he said in his closing remarks. He described in court how his tank column had come under fire. They stole a car to escape and the older man had been a witness. His superior ordered him to shoot, shouting at him. After initially refusing, he gave a short burst of fire. The defendant later surrendered himself to captivity because he wanted to live and 'not fight,' he said, adding: 'I do not deny my guilt.' Another Russian soldier who was captured with him confirmed the version in court. The commanding officer was 25 to 30 years old, the witness said. They had been told that the officer was now dead. The prosecution had asked for life imprisonment. The defence argued for acquittal, saying the soldier was carrying out an order. The trial began last week. Shelipov's widow joined the prosecution demand for life in prison, but said she was not opposed to him being handed to the Russians in exchange for one of the Ukrainian fighters captured in Mariupol. According to Moscow, more than 2,400 Ukrainian fighters have now been captured from the Azovstal steelworks in the port city. Ahead of the sentencing, Moscow said it was looking for possibilities to help the defendant. For Ukraine, this is likely only the beginning of the country's reckoning with the countless war crimes committed since the start of Russia's invasion three months ago. Russian troops have since withdrawn from the north-eastern regions of Kyiv, Chernihiv, and Sumy. Their withdrawal has revealed reports of atrocities that have triggered horror around the world. More than 400 were found dead in the Kyiv suburb of Bucha alone. Many crimes have also been documented in the suburbs of Irpin and Borodyanka. In a recently published interview on the editorially independent Russian website Meduza, the mother of Vadim Sh. said she had only learned about the war in Ukraine when she heard about her son's imprisonment on March 1. She said that she now knew many parents whose children were in Ukrainian captivity, adding that she had written to Putin saying she wanted her son back, but had not received an answer.