Even in cases where we can’t be sure like perhaps this one, we can infer things. The result with the least number of presuppositions is the likely actual occurrence as per Occam’s razor.

Which require more presupposition, that a forward going army killed people on the roads, or that a country brought their own dead on the street, possibly clothed them up as civils or whatever and placed them neatly there?

Also, do look at the satellite pictures and BBC’s debunk on the ridiculous claims of Russian propaganda.