A 46-year-old man has been jailed for 10 weeks for assaulting a woman by kicking her in the head.
Simon Collins was filmed by a bus passenger lashing out at the woman on 17 October as she lay prone in Oxhill Road, Handsworth.
The footage was shared widely on social media and Collins was arrested four days later. The woman was never identified.
Collins was sentenced at Birmingham Magistrates' Court on Monday.
West Midlands Police said it had brought a rare "victimless" prosecution against Collins, of Newcombe Road in Handsworth, Birmingham.
The force said in the footage the woman was lying motionless on the floor and "clearly in need of help, yet Collins walked past and kicked her forcefully in the head".
Inquiries were made at GP surgeries and hospitals to try and find the woman, but she was never traced.
Officers said that because the victim never came forward, the full extent of her injuries could not be identified and therefore Collins had to be prosecuted for common assault instead of grievous bodily harm.
PC Paul Minshull added: We can take suspects to court in cases where the victim hasn't been identified, or where the victim won't cooperate, if we believe it's in the public interest and the right thing to do."