You find that its false because you do not have knowledge of the facts. It has nothing to do with Russian propaganda. The missile fired in 2015 was being examined in Ukraine by Ukrainian people in Alchevsk. The pictures of the one from the Kramatorsk train station are screen captured from footage filmed by an Italian news crew.

Obviously they were originally Russian made. They are soviet era SS-21s. They were deployed in Ukraine when they were part of the USSR so they had many of them.

This 90 second video illustrates the point very well https://www.bitchute.com/video/oUZT9dWtadiG/

Aside from that it is ludicrous that you would claim Ukraine does not kill their own people. What do you think they have been doing for the last 8 years? Why do you think the video of that missile was there in 2015? The Ukraine military has an 8 year long catalogue of atrocity against the people of the Donbass region and right now they are just continuing the same thing so western media trolls can blame Russia for it.