Well doesn't sound like it was the scum that carried it out.
What would the Russians gain from killing their own people? - they don't need an excuse to level Kiev - that's a certainty to happen anyway if Zelensky stays much longer.
So who else is likely sow ** in Moscow at this time?
I think one prominent person has stated publicly that Putin had some "nasty surprises coming up" - with that person's track record she/he would be my number one suspect.