Presumably the BTC, or at least some of it can be traced if the investigators were motivated, skilled and had the means. In this particular case...
"We don't know" ... oh heavens.... of course they don't know :D If it were my money I know exactly where I'd start looking for it.
As the saying goes, "a fool and his money". Those two are long gone to go live it large in the Middle East or Asia.
There's a money printing circus around the world today. It's an eventual race to the bottom. At some point - not just yet - the wheels may come...
For one thing, Chinese design & manufacture the highest performing bitcoin miners and the way that scene tends to work is that they run those...
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