A court in Ukraine has jailed a Russian tank commander for life for killing an unarmed civilian at the first war crimes trial since the invasion.Captured soldier Sergeant Vadim Shishimarin was convicted of killing Oleksandr Shelipov, 62, in the north-eastern village of Chupakhivka on 28 February.He admitted shooting Mr Shelipov but said he had been acting on orders and asked forgiveness of his widow.Multiple other alleged war crimes are being investigated by Ukraine.