You just have to see it with your own eyes.
These are the former armed insurgents of the so called "Maidan Self-Defense Forces", nowadays the "Kiev-2" battalion of the Ministry of Internal Affairs of Ukraine.
They seized a man; made him undress; beat him; tied his hands and threw him into dirt.
It's Autumn; and it's not that warm round there.
They pose with their beaten and bleeding victim lying in the foreground.