How would a warrant work in this case? BestBuy reports that they found child porn, but proceeds to give the computer back to the owner? Is that legal or are th

How would a warrant work in this case? BestBuy reports that they found child porn, but proceeds to give the computer back to the owner? Is that legal or are they trafficking? Meanwhile the FBI goes and requests a warrant based upon what they heard from BestBuy? That seems almost more slippery to me, does the FBI just need to "hear something" from somebody to get a warrant to look around? Or is it even possible for them to get a warrant in a case like this, save for BestBuy involving them like they do? This seems like the step that causes a warrant to be issued for more stuff. How I'd imagine it goes: 1) BestBuy worker finds child porn while doing normal work. 2) BestBuy worker does "extra work" to report child porn to FBI and does not return the machine, he files some paperwork, maybe makes a full backup, etc.. 3) BestBuy employee signs a deposition, BestBuy hands machine over to FBI with owner's information 4) BestBuy or BestBuy employee gets some money (I'd think BestBuy would want their cut but that's a detail, maybe they're cool to their people in that way) for doing "extra work" and reporting crime. 5) FBI and federal prosecutors look at evidence, seek warrant for other evidence, start planning case. Perhaps said warrant makes a big case or identifies nothing else. 6) BestBuy worker may potentially be called to testify. Sadly at the end of the day $500 isn't going to pay much for a personal lawyer and I think it would be ill-advised to show up to court in any capacity in a federal case without one. ...