Law enforcement will consider you a suspect from the very first moment you begin using cryptocurrencies and/or Tor. It's something they do not like at all. The days of dark web will 'fence' you if you're careful to the extreme.
There was one pedophile that was properly using Tor and couldn't get traced down until intel gave him a "young girl's explicit video" that had some code/script embedded in it, played it online and leaked the info to the authorities. That's how he got caught. If you're using Tor to be completely hidden especially for criminal activity, you have to use it properly and extremely cautious.
This is why they for now like Bitcoin. It's fully transparent, so you need no extra access key or permissions to see all of the addresses and where their money went. Easy to link identities of those who are silly enough to believe Tor Browser is enough to commit crimes over the internet anonymously.