Withdraw coins to address
Send them to another address that was generated through Tor/i2p or offline
Repeat again
Cash out the coins on localbitcoins

There's no possible way any court can prove you own the middle addresses unless they find your private keys or you generated them using a clear connection. So if you use full disk encryption, and you aren't retarded, you can basically be as pseudo anonymous as you want using bitcoin. You can even split them up into hundreds of different addresses, run them through a laundry service and then destroy your encrypted disks that generated the wallet(s) if you were that paranoid.

I don't know of any court case where somebody was caught through Bitcoin. The weird Mitt Romney extortion attempt, they found they guy from the USB thumbdrive he mailed with the ransom demands and recovered his old pictures.