I'm so sorry that happened. It doesn't matter if it was belly button lint and a tic-tac or $1,000...EITHER WAY IT ISN'T THEIRS!!!
Hopefully GODMA (I believe in 'karma', but only in the sense that it's GOD that does it!) will take care of this punk. In a perfect world where we don't get offended and upset when someone touches our stuff, it'd be nice to reach out to the kid and see exactly what his problem is and he'd turn his behavior around and be a great kid.....but as much as we'd like it to be, that isn't the world we live in all the time. Kids are disrespectful and really do not expect or believe that there are repercussions for bad behavior.
Showing him some of God's forgiveness would be very hard....but maybe just what he needs. Seems he wants your attention more than he wants your stuff. Whether he wants it for good reasons or bad, who knows. maybe he has no dad. Maybe he has no older brothers and thinks your cool...and he's too messed up socially/emotionally to start a conversation.
Maybe he's just a horrendous brat that needs a good butt-whooping.
No matter what, I am sorry this happened to you! Good luck!