Like for example: a drug raid, or they’re accusing you of illegal hacking, or some sort of TheSilkRoad type of stuff.
Assuming the original investigation find no evidence and leads to no charges, could they use the pirated content that you have as a last ditch effort to get you in prison? Not distributing, just personal use.
Not limited to any specific jurisdiction, just want to know what happens in general.
Not a lawyer, but my understanding is if they find illegal stuff during discovery for an unrelated charge, you can be charged for that as well. One caveat would be if the original search was illegal, so say you see some police in public and you start recording them, then they come and take your phone away as evidence for the crime of recording police, which everyone knows is not actually illegal. They did not have the right to take your phone to begin with so anything they find on your phone then should be not admissible as evidence against you. Again, not a lawyer.
The thing about illegal searches is once they find something it is easy to put it back - then you go look for evidence and soon you have enough to get a warrant to search that. few criminals are so good at hiding their tracks that the police can’t find enough evidence once they know who to look at.