A Ukrainian state prosecutor asked a court on Thursday to sentence a Russian soldier Vadim Shishimarin to life in prison for killing an unarmed civilian in the first war crimes trial arising from Russia's Feb. 24 invasion.

On Monday, he has sentenced to life imprisonment. The relevant decision was made by the court in connection with the premeditated murder of a civilian in Sumy region.

A 21-year-old Russian tank commander, asked widow Kateryna Shelipova to forgive him for the murder of her husband, Oleksandr, in the northeast Ukrainian village of Chupakhivka on Feb. 28.

The investigators have been collecting evidence of possible war crimes to bring before the International Criminal Court (ICC) in The Hague.