There is a little thing called proof if you have it and they pay your fine (and they should) that is about all you can do. The game does not have any way to impose a prison sentence on a player so the best you could hope for would be some Class A role play and get the smuggler to agree not to come back for a set amount of time to reflect a prison term. maybe even getting them to not use that ship at all for say a week or what ever can be worked out. But you would be required to post proof in the form of screen shots of their cargo.
Not just saying that they had X amount and wanting them to take your word for it. As i have said before i have been told to halt by lawfuls who just scanned my ID and had no idea what or how much cargo i was hauling and i am sorry but the line "well i know you had contraband you hot docked" just doesn't cut it i hot dock regardless of what i am hauling
