That’s not entirely true - I think the official term is creative reconstruction -and basically once they have evidence then they go back and document all of the things that, with perfect hindsight, would have caused reasonable suspicion so that obtaining the evidence then becomes justified. So John Doe has been caught transporting narcotics, and with perfect hindsight we know that John drives a much more expensive car then his his income allows, so that raised suspicion and justified searching the vehicle where the narcotics were found. That’s how it seems to work more or less.