Realistically, I don't need to do that. In an investigation, they'd eventually get a warrant for your electronics. They'd comb through them, and probably find

Realistically, I don't need to do that. In an investigation, they'd eventually get a warrant for your electronics. They'd comb through them, and probably find your bitcoin wallet. In the event where it's relevant to the case that they see the contents of your bitcoin wallet, you'd be compelled to decrypt it. So they wouldn't ever have to tie your IP address to a transaction - the feds or local police would just get your wallet and trace backwards from there.