Apparently the timeline of the discovery of the Bucha massacre (as reported by the NYT!) is questionable, since the mayor didn't mention anything about mass killings when the town was liberated. Also it neatly coincides with a Ukranian op to clear the area of "saboteurs and collaborators."
I gave Ukraine some benefit of the doubt about the news when it broke because the presence of dozens or hundreds of dead bodies to fake a massacre just seemed unbelievable. It seems I was at least partially wrong.
This scenario goes along with video of what's supposedly Azov (or another neo-Nazi group) accosting and killing civilians trying to leave Mariupol.
There were many reports of Ukranians burying shelling victims in mass graves through the war.