He posted in-game chats, village names, and screenshots of the entire thing. I'm not sure how much more proof you want. Whether this information leads to Zachary09 or not is hard to say but OP isn't accusing others without basis.
Well if i would want to kill or gank someone I wouldn't use same name or similar to my main. Probably not everyone think same way

And this prof means nothing to me. Maybe to you coz you already belive it's him.
Proof of village name tells only the name of village he was trading from not who did it

Anyway i will left you guys solve this one. Advice: Next time think before you trading with ppl you don't know or their tread is new 1day.