my child has had threats of violence made to him by a child who suffers from Asperger Syndrome (which was only diagnosed at the age of 9) he is now 11 he has threatened to get a knife and kill him, bullies him and will not leave him alone. He attends a mainstream school which my 5 year old also attends. He constantly harrasses my son and comes out with inappropriate language e.g you f*** in the *** / you f*** in the butt. Should we be worried and if so what action do we take ?, the parents are not concerned about his language or actions and say that our 5 year old needs to understand that it is because of his Asperger Syndrome that he acts inthis way.