Yeah, what would happen if there were several different sets of prints on the can?
I mean, it's no crime if you walk past and see a can of POR and pick it up to read the label (not forgetting that the 'shop is full of mechanics who might be interested in buying some to use themselves for their own projects) and putting it down again, and then there's the prints from the guy who put the stuff on the shelf in the store you bought it from, and the prints of the cashier, etc etc.
As Raul says, even if it's got the prints of a guy you don't like on it, that doesn't automatically make him the perpetrator. To convict, you need "Proof, beyond
reasonable doubt". Cheers, Terry.