My child is being punched at kindergarten by a girl who also continually does things to him. For example, putting soap on his chair, messing with his outdoor clothes, etc.
The teachers know and have talked to the girl’s parents, but the behavior continues. My child is scared to go and cries about it sometimes. I’m not entirely sure how to handle it, because that’s the teachers job and I’m not there to help or see it.
Eventually, I’m considering involving the police, but that seems pretty last resort.
Any suggestions?
Edit
The director and teachers are all aware of the issues


Talk to other parents. There’s a non-zero chance that your child is not the only one. Also, for children that young, a lot of the times such behaviour comes from negative home experiences - be it their own parents bullying them, or even just neglect (no corrections, guidance, etc), so you can’t always expect help from the kid’s parents. However, if you manage to get the involvement of other parent(s) then it becomes more serious, and hopefully will have the staff listen and act.