QLD High school student sexual harrasment???

[Lochlan Womersley]

So one night my sister had the idea to message a member of my year twelve cohort. trying to get a reaction. he then drove 20 ish km to my house and filmed my street and my house and sent it to me. now i posted that video of him in my street with him having no real reason to be there at all.i then got replies from heaps of girls saying that hes either tried talking to them or hanging out with them. some even said he has stalked their house before.this guy is 17 and they are between 15-16. now i asked my neighbour for legal advice (she works in the child court) so the next day my sister and i went to the police station to make a claim.from there some of the girls have gone in and also made statements, one of the girls states that she continues to have anxiety attacks whenever she sees him hears his name. (They were in a unofficial relationship that turned abusive and controlling etc). Now thats its first day back at school, hes walking around talking smack saying he wants to sue me for deformation. So thats where i am today. now the backstory is that. this guy comes to school and tells everyone hes had sexual contact with younger girls. He states 14-15 when hes 17. he talks it up and talks about what would happen if he were to have sexual contact with my sister. i dont know what to do as of now since hes said that.