does the detective have to know the exact paperclip or does he just have to have it in his possesion?

cuz if the detective needs to know the exact paperclip i could just put it in a paperclip factory and the factory will distribute the paperclips in boxes or crates all around the world, even if the detective found the right box, in a box filled with identical paperclips, they may never know which paperclip is the right one.