Since we are talking about getting murder convictions without a body or a weapon, I'd like to point out a case where just that happened. The case of Hans Reiser, who killed his wife Nina. The prosecutors had no body and no murder weapon, and he was found guilty of 1st degree murder.
https://en.wikipedia.org/wiki/Hans_Reiser
After he was convicted, he led the police to where he'd buried her body. He strangled her with his hands and so there was no weapon.
To keep this on topic, to say that there is evidence of it beyond Postle making correct plays of the time isn't truthful. Heck, we can't even point to the fact that he won consistently. There are sessions on the spreadsheet right up until the end where he wasn't in "god mode". Without access to his phone and texting records we can only speculate that he was receiving information about other players holdings with it. Looking at his crotch isn't an indication of cheating. Without physical evidence of a bone conducting headset we can only speculate on that too. A "bump in the hat" is just that. Who happened to be in town when he was winning is highly circumstantial at best. Having his keys on the table is proof of nothing.
If this case went to a criminal trial today based on what we know in this thread, there would be less than a 1% chance of conviction and I think that's being generous.
Do I think he cheated? Almost certainly. But there really isn't any proof of it.