Would you happen to have any proof of this user killing your villagers? Could you also try get a better video of what blocks he has placed around your area as it's kind of hard to tell in the video you have provided.
unfortunately, I do not have video evidence of him killing the villagers as I just turned them from a zombie and when I had my back turned they proceeded to kill them so by the time I got over there they were all dead. also one of my friends has cleaned up the blocks that was placed so i am unable to show the extent of that damage.
I don't think I can accept this report sorry, by looking at the video it doesn't show any of the villagers being killed and it doesn't really show any of the blocks placed by the user (There is a little I can see but that could of been placed by anyone and your friend has already removed them so it's a bit late to check block logs) If this person decides to grief you or break any rules in the near future, feel free to report them again. For now, I'll be closing this report. Thank you for the report. Unfortunately the evidence provided is insufficient. Should you gain more evidence in the future, do not hesitate to report this player(s) again. Kind regards, The Staff