I've seen some other stuff of guys with blue tape doing stuff. In this case, some of the victims don't have proper Russian uniforms. This looks like a wait and see thing to me.
And, by the way, I'm not saying that Ukrainians won't or can't do that kind of stuff. I would be shocked if they haven't already done stuff like that. They have a lot of untrained, non-professional, newly enlisted military personnel (including civilian militias) defending their own neighborhoods (not just their homeland), in a war in which the aggressor is shelling civilians homes on purpose. Lots of women and children dying. I would be shocked if the Ukrainians showed 100% military professionalism when they get their hands on the perpetrators.