A child threatened to stab my son last week at school, I have been in and spoke to the teacher, but today a parent told me that the child that has done the threatening had a knife on him last year that the head took off him. I have been in today and spoke to the head but she can't guarantee me that my son won't come to harm! Should I contact the police and ofstead or am I overthinking things. I'm very worried for my sons safety.