At age 13-14 you're looking at your typical deviant. Even if he's rather young, he still knows what he's doing (granted there aren't existing mental issues)
. I believe you acted appropriately in that particular situation with things as they were, though if it were me, I don't think I would have slapped his hand... the kid would have been on the ground and I would have told the clerk to call police and tell them a teen tried to disarm you. In most states you would have been justified in defending yourself and others around you. I wish the responding Officer would have been far more thorough in speaking to the mother about keeping an eye on her child, especially if he has tendencies like those. It's very good you had that Serpa 3, though. Good job.