Legal penalty for vandalism of mailboxes?

Last night I was invited by some friends to go out and have some fun. We stopped and bought mortars at a fireworks store and put them in 3 seperate mailboxes. The police pulled us over on the interstate and I admited that we were the ones who had done it. They didn't damage the mailboxes at all and the cop let us go but took all 3 of our phone numbers and said he was gonna go talk to the people and see if they wanted to press charges. I don't know how he'd know which houses to go to because we didn't damage any of the mailboxes at all. Should I expect for him to call me back? It's been almost 24 hours and we've heard nothing from him. I also said that I'd be willing to pay to replace the mailboxes. I've never been in ANY trouble with the law and I've got a perfect record. If he does call me what punishment should I expect? I live in Tennessee.