I am so sorry your son was raped!
It's really shocking that cops and detectives are not taking it seriously and not registering a case. What's even more shocking is the teacher who wants to keep his job, while children of his school are getting raped!!

This is no joke, this is a very, very serious matter!

You cannot take this lying down. I think you should meet up with the school principal and complain about the woman and also about the coach. Maybe you can get child protection services involved, they have the muscle power to get the case registered and push for execution, since many children's lives is at stake here.

The Penn State Sex abuse case came tumbling out because someone pushed for it and kept pushing.

If all that fails, maybe you can get media involved, though that should be the laaaaaast resort, only for justice, since media attention can distress victims.

Wish you all the best for it.

And while getting justice for your son is only one side it, the other side, a more important side is for your son to heal his emotional wounds. Pls consult a therapist and take your son to it. Healing and moving on is far more important that justice.

Good luck.