Where the lines of justice are drawn

So about a week ago, J gets a theft report from a woman who says five sets of her Bengals tickets were stolen. He asks if she knows who could have taken them. Her daughter's ex-boyfriend was recently at the house, and he seems a likely candidate. So J calls this kid, asks if he's got the tickets. Naturally the kid says no. J asks if the kid knows what will happen to the people found in those seats. Between you and me, J working in a different county than Paul Brown Stadium, this is kind of an empty threat, but it scares the kid a bit. Unfortunately there's not much to go on suspecting the kid other than the woman's guess.

A few days later J gets a call from the woman. She says her daughter knows the night manager at the Frisch's where this kid works, and the night manager says the kid has been trying to hawk Bengals tickets. If J gets a statement from the manager, this could be enough for the prosecutor. Since 5 sets of Bengals tickets are worth more than $500, this is a felony theft charge.

Another few days go by, and J gets another call from the woman. She says she got an envelope in the mail with three sets of the tickets, and $300, along with a letter from the kid. He apologizes for taking the tickets, says he can't 'find' the other two sets (must have successfully sold them) but here's money to make up for it. Please don't report him to the cops, he doesn't want to go to jail. This is admission of guilt, and plenty of evidence to support charges. The woman wants to know what she's supposed to do with the money.

Simply enough, she didn't misrepresent herself to the kid by telling him to pay for the tickets. She just wanted her tickets back. By filing the theft report, the Bengals reissued her tickets, so she's not out any money. The kid didn't get away with it, and attempted to make it right.

Here's the question: The daughter's ex-boyfriend obviously made restitution for his crime. Do charges still need to be pressed against him? J tells the woman that technically, being felony theft, the responsibility falls on HIM to file the charges. However, if she wants, she can sign a drop-investigation form and it will all go away. He gives her a few days to think about it.

In my mind, why bog down the system with this case? The kid paid his debt, she got her tickets back, all's righted. J responds that the kid committed a crime and needs to pay. I respond that he did pay. He says, "but only because he thought he was going to jail, and not because he had a change of heart." So what? People don't have a change of heart by going to jail, either. In discussing it with others, I hear "Well maybe he'll think he can get away with it next time." Right, and people who go to jail never repeat their crimes either.

Did he pay his debt? Was justice served? Should he still go to jail? If so, why do we impose fines for lesser crimes too?