Classmate stole my hoodie?

Alright, this is not a troll and I am dead serious, my classmate stole my hoodie.

Background: it is this really weird kid known for picking abandoned pencils or notebooks, or taking text books from other kids at the bookshelf. (our school made us sign our textbooks, then put it on a shelf dedicated to a grade when it is not used).

Incident: So I bought this really nice Supreme Box Logo hoodie I earned with money from mowing my neighbor’s lawn and chore money.

So, I bought this hoodie a week ago, and yesterday, this kid is eyeing it like the most important thing in the world. I just ignored him and put in in my locker ( our school lockers have no locks so kids can grab things quickly and not waste time turning lock combinations) because it is pretty warm because it is Miami. Later that day, my hoodie is gone. So I’ve been asking all my teachers and friends if they seen it, and all the replies are no. I think I checked the lost and found for a hundred times now. Then, three days later the kid is wearing it! I knew he stolen it, because he got a reputation for it. I told all my teachers that he stole it, but they said he bought it the same one and I am mistaken. What should I do?