Hmm haven't we discussed this to death?
It is not possible for the police or any entity to tell, just by looking the transactions themselves. In fact, without any actual link to evidence, the transactions can't be identified. If the authority can get one of the addresses/transactions involved, they could get the whole link of addresses that are related but that isn't possible all the time and its rather inaccurate and useless.
I agree that this is impossible because it is a completely different area for this. And for now, I think it's going to be very difficult to turn anything. So don't worry about it.