Thank you so much for taking the time to reply and reaffirming that it's a stage kids sometimes go through. I've never heard of this before, at the middle school level when kids are stealing it's obviously a different story, so to think of him stealing as a "phase" is hard for me to swallow.

You are the second person to reply to talk about how we should emphasize the social emotional aspect of how stealing makes others feel. Thank you for echoing this because my instinct is to come in hard and swift with punishments for something I see as egregious misbehavior, but I need to remember that developing his social and emotional understandings is very important in this scenario. After all, I wouldn't steal even if I knew I wouldn't be caught, why, because I have a strong sense of empathy and my guilt would absolutely eat me alive. I wouldn't be able to forgive myself. So you and the other commenter are right that it's very important to make the conversations with him less about punishments (though those could still apply, potentially) and more about what is internally right.

As for the reason why he stole, he is very interested in cars and vehicles. He has an embarrassment of toys, truly an insane amount of toys he likes, at both my sister's place and at the elder relatives' house. However, when he saw small cars at his school, he said he took them because he liked them and he wanted to play with them at home. We were pretty upset by this greed considering that his toy collection is already the largest either of us have ever seen (rich relatives + unlimited toys = entitled kid). I feel that he felt entitled to the toys and that's why he took them. It's greedy and we explained to him that those toys belong to his teacher and are to be shared by everyone in the class. I'm really hoping he can get it together, as a teacher it's very frustrating that he is doing this in a school environment.

Thank you again for hearing me out and taking the time to reply. I appreciate it.