A 21-year-old Russian soldier has asked a woman to forgive him for shooting dead her husband as he rode his bike.
Sergeant Vadim Shishimarin admitted murdering Oleksandr Shelipov, a civilian, as Russian soldiers drove into the village of Chupakhivka four days into the invasion.
He pleaded guilty to the 28 February murder when proceedings started on Wednesday at a Kyiv district court.
It is the first war crimes trial of the Ukraine war.
On Thursday, a Ukrainian prosecutor asked the court to sentence him to life in prison for killing the 62-year-old.
Shishimarin cut a forlorn figure in court, dressed in a tracksuit and with his shaven head lowered.
Addressing Mr Shelipov’s widow Kateryna, the soldier said: “I acknowledge my blame… I ask you to forgive me.”
The Kremlin claims it has no information about the trial and that the absence of a diplomatic mission in Ukraine means it cannot help.
Giving evidence, Mrs Shelipova said she had heard distant shots fired from their yard on the day of the killing.
“I ran over to my husband, he was already dead. Shot in the head. I screamed, I screamed so much,” she said, her voice trembling.
Mrs Shelipova told the court her husband had been unarmed and was dressed in civilian clothes.
She said they had a 27-year-old son and two grandchildren.
‘Shot in head while cycling and on the phone’
Ukrainian prosecutors say Shishimarin and four other servicemen had stolen a private car to escape after their column was targeted by Ukrainian forces.
As they arrived in Chupakhivka, about 200 miles east of Kyiv, they saw Mr Shelipov cycling and talking on his phone.
Prosecutors said Shishimarin was ordered by another soldier to kill him to stop him reporting their presence.
He’s said to have fired several shots through the car’s open window at Mr Shelipov’s head.
He died a few metres from his home.
When asked if he had been obliged to follow an order that amounted to a war crime, Shishimarin replied “no”.
He told the court: “I fired a short burst, three or four bullets.”
The soldier said he was from Irkutsk Oblast (a region in Siberia) and is the eldest of five children.
Mrs Shelipova said she would not object if he was released to Russia as part of a prisoner swap to get “our boys” out of the besieged city of Mariupol.
The trial comes as many Ukrainians hope Russia will hand over captured soldiers as part of an exchange.
Some senior lawmakers in Russia have called for Azov regiment fighters, part of Mariupol’s last stand at the Azov steel plant, to be put on trial.
Oleksandr Shelipov’s killing marks what Ukraine and much of the Western world say is the tip of the iceberg.
Ukraine has said it has identified more than 10,000 possible war crimes.
Russia continues to deny targeting civilians or having any involvement in war crimes.