The FBI/private companies have specialized tools for tracking Bitcoins throughout their lifespan. All the data is out in the open so there is no hiding unless he converted to Monero anonymously.
1) My understanding is, every transaction in bitcoin is public knowledge forever as part of the forever growing block chain. That is, there is no way to ever remove a transfer.
2) The only anonymity built in bitcoin is to hide your identity with pseudonymity, nobody necessarily knows your bitcoin address you are using. However if you are buying coins with credit card for example from person A and spend those at person B, person A will know that you have just spend that money at person B, and person B will know that you bought the coins from person A.
3) The only way(?) to hide, make the transactions anonymous is via tumbling, that is you send your coins into a huge account outside your control that aggregates maybe millions of $ from thousands of people and then sends them out again into random addresses. Nobody except the provider of the tumble service knows where your money went, making you anonymous, your money untraceable. I assume you want to repeat this process a few times with different tumble services.
Is that correct? I'm no expert. Also with 3) how feasible is that with $130 million? I mean to successfully tumble wouldn't I need at least double the amount probably much much more? How large are the tumbles in services such as bestmixer.io? Also it seems to me that with enough heuristics even tumble services could potentially be traced back, this doesn't seem impossible to me?
How feasible to do this with $130 million? Yesterdays trade volume for monero was 75 million (thus actual on chain tx's are much less). So it would take a while to do this without drawing attention. I don't have a lot of faith in pure bitcoin tumblers. Possibly scams or fraud. Im yet to see one that works as expected.
it might be wasabi wallet. not 100% though